# kb

id: escape-character-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Escape_character-1.md
category: reference
title: Escape character - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Escape_character
date_saved: 2026-05-05T05:30:47.324095+00:00
instance: kb-cron
parent: escape-character-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 6, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Escape_character/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/escape_character/index.md?plain=1 "Folder: en-us/glossary/escape_character \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FEscape_character&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fescape_character%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FEscape_character%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fescape_character%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2Ff69b6693212029ce4b9fa0c753729044577af548%0A*+Document+last+modified%3A+2025-11-06T14%3A49%3A20.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: event-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Event-0.md
category: reference
title: Event - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Event
date_saved: 2026-05-05T05:30:49.706626+00:00
instance: kb-cron
parent: event-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Event#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Event#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: event-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Event-1.md
category: reference
title: Event - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Event
date_saved: 2026-05-05T05:30:49.706626+00:00
instance: kb-cron
parent: event-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Event/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/event/index.md?plain=1 "Folder: en-us/glossary/event \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FEvent&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fevent%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FEvent%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fevent%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: exception-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Exception-0.md
category: reference
title: Exception - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Exception
date_saved: 2026-05-05T05:30:52.203492+00:00
instance: kb-cron
parent: exception-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Exception#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Exception#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: exception-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Exception-1.md
category: reference
title: Exception - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Exception
date_saved: 2026-05-05T05:30:52.203492+00:00
instance: kb-cron
parent: exception-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Exception/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/exception/index.md?plain=1 "Folder: en-us/glossary/exception \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FException&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fexception%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FException%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fexception%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: expando-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Expando-0.md
category: reference
title: Expando - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Expando
date_saved: 2026-05-05T05:30:54.581662+00:00
instance: kb-cron
parent: expando-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Expando#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Expando#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: expando-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Expando-1.md
category: reference
title: Expando - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Expando
date_saved: 2026-05-05T05:30:54.581662+00:00
instance: kb-cron
parent: expando-glossary-mdn-20260505-0
summary:
# Expando Expando properties are properties added to [DOM](https://developer.mozilla.org/en-US/docs/Glossary/DOM) nodes with [JavaScript](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript), where those properties are not part of the [object's](https://developer.mozilla.org/en-US/docs/Glossary/Object) DOM specification: The term may also be applied to properties added to objects without respecting the object's original intent, such as non-numeric named properties added to an [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array). ## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Expando/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/expando/index.md?plain=1 "Folder: en-us/glossary/expando \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FExpando&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fexpando%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FExpando%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fexpando%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt)


id: expando-glossary-mdn-20260505-2
file: data/developer.mozilla.org/en-US/docs/Glossary/Expando-2.md
category: reference
title: Expando - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Expando
date_saved: 2026-05-05T05:30:54.581662+00:00
instance: kb-cron
parent: expando-glossary-mdn-20260505-0
summary:
[Pseudo-class](https://developer.mozilla.org/en-US/docs/Glossary/Pseudo-class) 402. [Pseudo-element](https://developer.mozilla.org/en-US/docs/Glossary/Pseudo-element) 403. [Pseudocode](https://developer.mozilla.org/en-US/docs/Glossary/Pseudocode) 404. [Public-key cryptography](https://developer.mozilla.org/en-US/docs/Glossary/Public-key_cryptography) 405. [Python](https://developer.mozilla.org/en-US/docs/Glossary/Python) 406. [Quality values](https://developer.mozilla.org/en-US/docs/Glossary/Quality_values) 407. [Quaternion](https://developer.mozilla.org/en-US/docs/Glossary/Quaternion) 408. [QUIC](https://developer.mozilla.org/en-US/docs/Glossary/QUIC) 409. [RAIL](https://developer.mozilla.org/en-US/docs/Glossary/RAIL) 410. [Random Number Generator](https://developer.mozilla.org/en-US/docs/Glossary/RNG) 411. [Raster image](https://developer.mozilla.org/en-US/docs/Glossary/Raster_image) 412. [Rate limit](https://developer.mozilla.org/en-US/docs/Glossary/Rate_limit) 413. [RDF](https://developer.mozilla.org/en-US/docs/Glossary/RDF) 414. [Reading order](https://developer.mozilla.org/en-US/docs/Glossary/Reading_order) 415. [Real User Monitoring (RUM)](https://developer.mozilla.org/en-US/docs/Glossary/Real_User_Monitoring) 416. [Recursion](https://developer.mozilla.org/en-US/docs/Glossary/Recursion) 417. [Reflow](https://developer.mozilla.org/en-US/docs/Glossary/Reflow) 418. [Registrable domain](https://developer.mozilla.org/en-US/docs/Glossary/Registrable_domain) 419. [Regular expression](https://developer.mozilla.org/en-US/docs/Glossary/Regular_expression) 420. [Relying party](https://developer.mozilla.org/en-US/docs/Glossary/Relying_party) 421. [Render-blocking](https://developer.mozilla.org/en-US/docs/Glossary/Render_blocking) 422. [Repaint](https://developer.mozilla.org/en-US/docs/Glossary/Repaint) 423. [Replaced elements](https://developer.mozilla.org/en-US/docs/Glossary/Replaced_elements) 424. [Replay attack](https://developer.mozilla.org/en-US/docs/Glossary/Replay_attack) 425. [Repo](https://developer.mozilla.org/en-US/docs/Glossary/Repo) 426. [Reporting directive](https://developer.mozilla.org/en-US/docs/Glossary/Reporting_directive) 427. [Representation header](https://developer.mozilla.org/en-US/docs/Glossary/Representation_header) 428. [Request header](https://developer.mozilla.org/en-US/docs/Glossary/Request_header) 429. [Resource Timing](https://developer.mozilla.org/en-US/docs/Glossary/Resource_Timing) 430. [Response header](https://developer.mozilla.org/en-US/docs/Glossary/Response_header) 431. [Responsive Web Design (RWD)](https://developer.mozilla.org/en-US/docs/Glossary/Responsive_web_design) 432. [REST](https://developer.mozilla.org/en-US/docs/Glossary/REST) 433. [RGB](https://developer.mozilla.org/en-US/docs/Glossary/RGB) 434. [RIL](https://developer.mozilla.org/en-US/docs/Glossary/RIL) 435. [Robots.txt](https://developer.mozilla.org/en-US/docs/Glossary/Robots.txt) 436. [Round Trip Time (RTT)](https://developer.mozilla.org/en-US/docs/Glossary/Round_Trip_Time) 437. [Router](https://developer.mozilla.org/en-US/docs/Glossary/Router) 438. [RSS](https://developer.mozilla.org/en-US/docs/Glossary/RSS) 439. [Rsync](https://developer.mozilla.org/en-US/docs/Glossary/Rsync) 440. [RTCP (RTP Control Protocol)](https://developer.mozilla.org/en-US/docs/Glossary/RTCP) 441. [RTF](https://developer.mozilla.org/en-US/docs/Glossary/RTF) 442. [RTL (Right to Left)](https://developer.mozilla.org/en-US/docs/Glossary/RTL) 443. [RTP (Real-time Transport Protocol) and SRTP (Secure RTP)](https://developer.mozilla.org/en-US/docs/Glossary/RTP) 444. [RTSP: Real-time streaming protocol](https://developer.mozilla.org/en-US/docs/Glossary/RTSP) 445. [Ruby](https://developer.mozilla.org/en-US/docs/Glossary/Ruby) 446. [Safe](https://developer.mozilla.org/en-US/docs/Glossary/Safe) 1. [Safe (HTTP Methods)](https://developer.mozilla.org/en-US/docs/Glossary/Safe/HTTP) 447. [Salt](https://developer.mozilla.org/en-US/docs/Glossary/Salt) 448. [Same-origin policy](https://developer.mozilla.org/en-US/docs/Glossary/Same-origin_policy) 449. [SCM](https://developer.mozilla.org/en-US/docs/Glossary/SCM) 450. [Scope](https://developer.mozilla.org/en-US/docs/Glossary/Scope) 451. [Screen reader](https://developer.mozilla.org/en-US/docs/Glossary/Screen_reader) 452. [Script-supporting element](https://developer.mozilla.org/en-US/docs/Glossary/Script-supporting_element) 453. [Scroll boundary](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_boundary) 454. [Scroll chaining](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_chaining) 455. [Scroll container](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_container) 456. [Scroll snap](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_snap) 457. [SCTP](https://developer.mozilla.org/en-US/docs/Glossary/SCTP) 458. [SDK (Software Development Kit)](https://developer.mozilla.org/en-US/docs/Glossary/SDK) 459. [SDP](https://developer.mozilla.org/en-US/docs/Glossary/SDP) 460. [Search engine](https://developer.mozilla.org/en-US/docs/Glossary/Search_engine) 461. [Secure context](https://developer.mozilla.org/en-US/docs/Glossary/Secure_Context) 462. [Secure Sockets Layer (SSL)](https://developer.mozilla.org/en-US/docs/Glossary/SSL) 463. [Selector (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/CSS_Selector) 464. [Semantics](https://developer.mozilla.org/en-US/docs/Glossary/Semantics) 465. [SEO](https://developer.mozilla.org/en-US/docs/Glossary/SEO) 466. [Serializable object](https://developer.mozilla.org/en-US/docs/Glossary/Serializable_object) 467. [Serialization](https://developer.mozilla.org/en-US/docs/Glossary/Serialization) 468. [Server](https://developer.mozilla.org/en-US/docs/Glossary/Server) 469. [Server


id: extrinsic-size-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size-0.md
category: reference
title: Extrinsic size - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size
date_saved: 2026-05-05T05:30:57.385996+00:00
instance: kb-cron
parent: extrinsic-size-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: extrinsic-size-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size-1.md
category: reference
title: Extrinsic size - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size
date_saved: 2026-05-05T05:30:57.385996+00:00
instance: kb-cron
parent: extrinsic-size-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Extrinsic_size/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/extrinsic_size/index.md?plain=1 "Folder: en-us/glossary/extrinsic_size \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FExtrinsic_size&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fextrinsic_size%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FExtrinsic_size%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fextrinsic_size%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: frame-rate-fps-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/FPS-0.md
category: reference
title: Frame rate (FPS) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FPS
date_saved: 2026-05-05T05:31:00.125200+00:00
instance: kb-cron
parent: frame-rate-fps-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/FPS#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/FPS#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: frame-rate-fps-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/FPS-1.md
category: reference
title: Frame rate (FPS) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FPS
date_saved: 2026-05-05T05:31:00.125200+00:00
instance: kb-cron
parent: frame-rate-fps-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/FPS/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fps/index.md?plain=1 "Folder: en-us/glossary/fps \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFPS&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffps%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFPS%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffps%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: ftp-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/FTP-0.md
category: reference
title: FTP - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FTP
date_saved: 2026-05-05T05:31:02.795747+00:00
instance: kb-cron
parent: ftp-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/FTP#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/FTP#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: ftp-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/FTP-1.md
category: reference
title: FTP - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FTP
date_saved: 2026-05-05T05:31:02.795747+00:00
instance: kb-cron
parent: ftp-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/FTP/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/ftp/index.md?plain=1 "Folder: en-us/glossary/ftp \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFTP&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fftp%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFTP%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fftp%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: ftu-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/FTU-0.md
category: reference
title: FTU - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FTU
date_saved: 2026-05-05T05:31:05.207341+00:00
instance: kb-cron
parent: ftu-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/FTU#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/FTU#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: ftu-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/FTU-1.md
category: reference
title: FTU - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/FTU
date_saved: 2026-05-05T05:31:05.207341+00:00
instance: kb-cron
parent: ftu-glossary-mdn-20260505-0
summary:
# FTU FTU (First Time Use) is the app that loads when you run a newly-installed version of [Gecko](https://developer.mozilla.org/en-US/docs/Glossary/Gecko) on a [Firefox OS](https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS) device. You can use FTU to set many important options (e.g., timezone, Wi-Fi details, default language, importing contacts), or take the "Phone Tour" to find out more about your device. ## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/FTU/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/ftu/index.md?plain=1 "Folder: en-us/glossary/ftu \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFTU&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fftu%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFTU%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fftu%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache)


id: fallback-alignment-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment-0.md
category: reference
title: Fallback alignment - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment
date_saved: 2026-05-05T05:31:07.592308+00:00
instance: kb-cron
parent: fallback-alignment-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fallback-alignment-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment-1.md
category: reference
title: Fallback alignment - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment
date_saved: 2026-05-05T05:31:07.592308+00:00
instance: kb-cron
parent: fallback-alignment-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fallback_Alignment/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fallback_alignment/index.md?plain=1 "Folder: en-us/glossary/fallback_alignment \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFallback_Alignment&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffallback_alignment%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFallback_Alignment%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffallback_alignment%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: falsy-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Falsy-0.md
category: reference
title: Falsy - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Falsy
date_saved: 2026-05-05T05:31:10.056372+00:00
instance: kb-cron
parent: falsy-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Falsy#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Falsy#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: falsy-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Falsy-1.md
category: reference
title: Falsy - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Falsy
date_saved: 2026-05-05T05:31:10.056372+00:00
instance: kb-cron
parent: falsy-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Falsy/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/falsy/index.md?plain=1 "Folder: en-us/glossary/falsy \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFalsy&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffalsy%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFalsy%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffalsy%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: favicon-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Favicon-0.md
category: reference
title: Favicon - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Favicon
date_saved: 2026-05-05T05:31:12.845167+00:00
instance: kb-cron
parent: favicon-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Favicon#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Favicon#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: favicon-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Favicon-1.md
category: reference
title: Favicon - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Favicon
date_saved: 2026-05-05T05:31:12.845167+00:00
instance: kb-cron
parent: favicon-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Favicon/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/favicon/index.md?plain=1 "Folder: en-us/glossary/favicon \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFavicon&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffavicon%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFavicon%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffavicon%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: federated-identity-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Federated_identity-0.md
category: reference
title: Federated identity - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Federated_identity
date_saved: 2026-05-05T05:31:15.281463+00:00
instance: kb-cron
parent: federated-identity-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Federated_identity#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Federated_identity#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: federated-identity-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Federated_identity-1.md
category: reference
title: Federated identity - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Federated_identity
date_saved: 2026-05-05T05:31:15.281463+00:00
instance: kb-cron
parent: federated-identity-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Federated_identity/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/federated_identity/index.md?plain=1 "Folder: en-us/glossary/federated_identity \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFederated_identity&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffederated_identity%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFederated_identity%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffederated_identity%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fetch-directive-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fetch_directive-0.md
category: reference
title: Fetch directive - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive
date_saved: 2026-05-05T05:31:17.917098+00:00
instance: kb-cron
parent: fetch-directive-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fetch-directive-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fetch_directive-1.md
category: reference
title: Fetch directive - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive
date_saved: 2026-05-05T05:31:17.917098+00:00
instance: kb-cron
parent: fetch-directive-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_directive/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fetch_directive/index.md?plain=1 "Folder: en-us/glossary/fetch_directive \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFetch_directive&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffetch_directive%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFetch_directive%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffetch_directive%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fetch-metadata-request-header-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header-0.md
category: reference
title: Fetch metadata request header - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header
date_saved: 2026-05-05T05:31:20.815372+00:00
instance: kb-cron
parent: fetch-metadata-request-header-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fetch-metadata-request-header-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header-1.md
category: reference
title: Fetch metadata request header - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header
date_saved: 2026-05-05T05:31:20.815372+00:00
instance: kb-cron
parent: fetch-metadata-request-header-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Mar 31, 2026 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fetch_metadata_request_header/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fetch_metadata_request_header/index.md?plain=1 "Folder: en-us/glossary/fetch_metadata_request_header \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFetch_metadata_request_header&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffetch_metadata_request_header%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFetch_metadata_request_header%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffetch_metadata_request_header%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F81bf621759d3a52fdf737c2d75f186a0073d1406%0A*+Document+last+modified%3A+2026-03-31T18%3A16%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fingerprinting-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fingerprinting-0.md
category: reference
title: Fingerprinting - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fingerprinting
date_saved: 2026-05-05T05:31:23.349591+00:00
instance: kb-cron
parent: fingerprinting-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fingerprinting#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fingerprinting#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fingerprinting-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fingerprinting-1.md
category: reference
title: Fingerprinting - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fingerprinting
date_saved: 2026-05-05T05:31:23.349591+00:00
instance: kb-cron
parent: fingerprinting-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fingerprinting/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fingerprinting/index.md?plain=1 "Folder: en-us/glossary/fingerprinting \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFingerprinting&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffingerprinting%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFingerprinting%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffingerprinting%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: firefox-os-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Firefox_OS-0.md
category: reference
title: Firefox OS - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS
date_saved: 2026-05-05T05:31:25.733502+00:00
instance: kb-cron
parent: firefox-os-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: firefox-os-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Firefox_OS-1.md
category: reference
title: Firefox OS - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS
date_saved: 2026-05-05T05:31:25.733502+00:00
instance: kb-cron
parent: firefox-os-glossary-mdn-20260505-0
summary:
# Firefox OS Firefox OS is a discontinued open source mobile operating system developed by Mozilla. See [Firefox OS](https://en.wikipedia.org/wiki/Firefox_OS) for more details. Firefox OS was also often called Boot2Gecko before the project had an official name. ## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/firefox_os/index.md?plain=1 "Folder: en-us/glossary/firefox_os \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirefox_OS&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirefox_os%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirefox_OS%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirefox_os%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43.


id: firefox-os-glossary-mdn-20260505-2
file: data/developer.mozilla.org/en-US/docs/Glossary/Firefox_OS-2.md
category: reference
title: Firefox OS - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Firefox_OS
date_saved: 2026-05-05T05:31:25.733502+00:00
instance: kb-cron
parent: firefox-os-glossary-mdn-20260505-0
summary:
[Quaternion](https://developer.mozilla.org/en-US/docs/Glossary/Quaternion) 408. [QUIC](https://developer.mozilla.org/en-US/docs/Glossary/QUIC) 409. [RAIL](https://developer.mozilla.org/en-US/docs/Glossary/RAIL) 410. [Random Number Generator](https://developer.mozilla.org/en-US/docs/Glossary/RNG) 411. [Raster image](https://developer.mozilla.org/en-US/docs/Glossary/Raster_image) 412. [Rate limit](https://developer.mozilla.org/en-US/docs/Glossary/Rate_limit) 413. [RDF](https://developer.mozilla.org/en-US/docs/Glossary/RDF) 414. [Reading order](https://developer.mozilla.org/en-US/docs/Glossary/Reading_order) 415. [Real User Monitoring (RUM)](https://developer.mozilla.org/en-US/docs/Glossary/Real_User_Monitoring) 416. [Recursion](https://developer.mozilla.org/en-US/docs/Glossary/Recursion) 417. [Reflow](https://developer.mozilla.org/en-US/docs/Glossary/Reflow) 418. [Registrable domain](https://developer.mozilla.org/en-US/docs/Glossary/Registrable_domain) 419. [Regular expression](https://developer.mozilla.org/en-US/docs/Glossary/Regular_expression) 420. [Relying party](https://developer.mozilla.org/en-US/docs/Glossary/Relying_party) 421. [Render-blocking](https://developer.mozilla.org/en-US/docs/Glossary/Render_blocking) 422. [Repaint](https://developer.mozilla.org/en-US/docs/Glossary/Repaint) 423. [Replaced elements](https://developer.mozilla.org/en-US/docs/Glossary/Replaced_elements) 424. [Replay attack](https://developer.mozilla.org/en-US/docs/Glossary/Replay_attack) 425. [Repo](https://developer.mozilla.org/en-US/docs/Glossary/Repo) 426. [Reporting directive](https://developer.mozilla.org/en-US/docs/Glossary/Reporting_directive) 427. [Representation header](https://developer.mozilla.org/en-US/docs/Glossary/Representation_header) 428. [Request header](https://developer.mozilla.org/en-US/docs/Glossary/Request_header) 429. [Resource Timing](https://developer.mozilla.org/en-US/docs/Glossary/Resource_Timing) 430. [Response header](https://developer.mozilla.org/en-US/docs/Glossary/Response_header) 431. [Responsive Web Design (RWD)](https://developer.mozilla.org/en-US/docs/Glossary/Responsive_web_design) 432. [REST](https://developer.mozilla.org/en-US/docs/Glossary/REST) 433. [RGB](https://developer.mozilla.org/en-US/docs/Glossary/RGB) 434. [RIL](https://developer.mozilla.org/en-US/docs/Glossary/RIL) 435. [Robots.txt](https://developer.mozilla.org/en-US/docs/Glossary/Robots.txt) 436. [Round Trip Time (RTT)](https://developer.mozilla.org/en-US/docs/Glossary/Round_Trip_Time) 437. [Router](https://developer.mozilla.org/en-US/docs/Glossary/Router) 438. [RSS](https://developer.mozilla.org/en-US/docs/Glossary/RSS) 439. [Rsync](https://developer.mozilla.org/en-US/docs/Glossary/Rsync) 440. [RTCP (RTP Control Protocol)](https://developer.mozilla.org/en-US/docs/Glossary/RTCP) 441. [RTF](https://developer.mozilla.org/en-US/docs/Glossary/RTF) 442. [RTL (Right to Left)](https://developer.mozilla.org/en-US/docs/Glossary/RTL) 443. [RTP (Real-time Transport Protocol) and SRTP (Secure RTP)](https://developer.mozilla.org/en-US/docs/Glossary/RTP) 444. [RTSP: Real-time streaming protocol](https://developer.mozilla.org/en-US/docs/Glossary/RTSP) 445. [Ruby](https://developer.mozilla.org/en-US/docs/Glossary/Ruby) 446. [Safe](https://developer.mozilla.org/en-US/docs/Glossary/Safe) 1. [Safe (HTTP Methods)](https://developer.mozilla.org/en-US/docs/Glossary/Safe/HTTP) 447. [Salt](https://developer.mozilla.org/en-US/docs/Glossary/Salt) 448. [Same-origin policy](https://developer.mozilla.org/en-US/docs/Glossary/Same-origin_policy) 449. [SCM](https://developer.mozilla.org/en-US/docs/Glossary/SCM) 450. [Scope](https://developer.mozilla.org/en-US/docs/Glossary/Scope) 451. [Screen reader](https://developer.mozilla.org/en-US/docs/Glossary/Screen_reader) 452. [Script-supporting element](https://developer.mozilla.org/en-US/docs/Glossary/Script-supporting_element) 453. [Scroll boundary](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_boundary) 454. [Scroll chaining](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_chaining) 455. [Scroll container](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_container) 456. [Scroll snap](https://developer.mozilla.org/en-US/docs/Glossary/Scroll_snap) 457. [SCTP](https://developer.mozilla.org/en-US/docs/Glossary/SCTP) 458. [SDK (Software Development Kit)](https://developer.mozilla.org/en-US/docs/Glossary/SDK) 459. [SDP](https://developer.mozilla.org/en-US/docs/Glossary/SDP) 460. [Search engine](https://developer.mozilla.org/en-US/docs/Glossary/Search_engine) 461. [Secure context](https://developer.mozilla.org/en-US/docs/Glossary/Secure_Context) 462. [Secure Sockets Layer (SSL)](https://developer.mozilla.org/en-US/docs/Glossary/SSL) 463. [Selector (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/CSS_Selector) 464. [Semantics](https://developer.mozilla.org/en-US/docs/Glossary/Semantics) 465. [SEO](https://developer.mozilla.org/en-US/docs/Glossary/SEO) 466. [Serializable object](https://developer.mozilla.org/en-US/docs/Glossary/Serializable_object) 467. [Serialization](https://developer.mozilla.org/en-US/docs/Glossary/Serialization) 468. [Server](https://developer.mozilla.org/en-US/docs/Glossary/Server) 469. [Server Timing](https://developer.mozilla.org/en-US/docs/Glossary/Server_Timing) 470. [Server-side rendering (SSR)](https://developer.mozilla.org/en-US/docs/Glossary/SSR) 471. [Session hijacking](https://developer.mozilla.org/en-US/docs/Glossary/Session_Hijacking) 472. [SGML](https://developer.mozilla.org/en-US/docs/Glossary/SGML) 473. [Shadow tree](https://developer.mozilla.org/en-US/docs/Glossary/Shadow_tree) 474.


id: firewall-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Firewall-0.md
category: reference
title: Firewall - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Firewall
date_saved: 2026-05-05T05:31:28.265245+00:00
instance: kb-cron
parent: firewall-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Firewall#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Firewall#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: firewall-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Firewall-1.md
category: reference
title: Firewall - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Firewall
date_saved: 2026-05-05T05:31:28.265245+00:00
instance: kb-cron
parent: firewall-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Firewall/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/firewall/index.md?plain=1 "Folder: en-us/glossary/firewall \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirewall&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirewall%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirewall%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirewall%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-class-function-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First-class_Function-0.md
category: reference
title: First-class function - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First-class_Function
date_saved: 2026-05-05T05:31:30.661535+00:00
instance: kb-cron
parent: first-class-function-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First-class_Function#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First-class_Function#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-class-function-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First-class_Function-1.md
category: reference
title: First-class function - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First-class_Function
date_saved: 2026-05-05T05:31:30.661535+00:00
instance: kb-cron
parent: first-class-function-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 18, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First-class_Function/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first-class_function/index.md?plain=1 "Folder: en-us/glossary/first-class_function \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst-class_Function&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst-class_function%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst-class_Function%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst-class_function%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F13839b2979cc244034ffb1fe243240778b0cd23f%0A*+Document+last+modified%3A+2025-07-18T15%3A04%3A24.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-cpu-idle-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle-0.md
category: reference
title: First CPU idle - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle
date_saved: 2026-05-05T05:31:33.341067+00:00
instance: kb-cron
parent: first-cpu-idle-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-cpu-idle-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle-1.md
category: reference
title: First CPU idle - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle
date_saved: 2026-05-05T05:31:33.341067+00:00
instance: kb-cron
parent: first-cpu-idle-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First_CPU_idle/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first_cpu_idle/index.md?plain=1 "Folder: en-us/glossary/first_cpu_idle \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_CPU_idle&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst_cpu_idle%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_CPU_idle%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst_cpu_idle%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-contentful-paint-fcp-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint-0.md
category: reference
title: First Contentful Paint (FCP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint
date_saved: 2026-05-05T05:31:35.768049+00:00
instance: kb-cron
parent: first-contentful-paint-fcp-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-contentful-paint-fcp-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint-1.md
category: reference
title: First Contentful Paint (FCP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint
date_saved: 2026-05-05T05:31:35.768049+00:00
instance: kb-cron
parent: first-contentful-paint-fcp-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First_contentful_paint/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first_contentful_paint/index.md?plain=1 "Folder: en-us/glossary/first_contentful_paint \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_contentful_paint&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst_contentful_paint%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_contentful_paint%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst_contentful_paint%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-input-delay-fid-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First_input_delay-0.md
category: reference
title: First Input Delay (FID) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_input_delay
date_saved: 2026-05-05T05:31:38.234806+00:00
instance: kb-cron
parent: first-input-delay-fid-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First_input_delay#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First_input_delay#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-input-delay-fid-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First_input_delay-1.md
category: reference
title: First Input Delay (FID) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_input_delay
date_saved: 2026-05-05T05:31:38.234806+00:00
instance: kb-cron
parent: first-input-delay-fid-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First_input_delay/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first_input_delay/index.md?plain=1 "Folder: en-us/glossary/first_input_delay \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_input_delay&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst_input_delay%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_input_delay%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst_input_delay%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-meaningful-paint-fmp-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint-0.md
category: reference
title: First Meaningful Paint (FMP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint
date_saved: 2026-05-05T05:31:40.603354+00:00
instance: kb-cron
parent: first-meaningful-paint-fmp-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-meaningful-paint-fmp-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint-1.md
category: reference
title: First Meaningful Paint (FMP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint
date_saved: 2026-05-05T05:31:40.603354+00:00
instance: kb-cron
parent: first-meaningful-paint-fmp-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First_meaningful_paint/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first_meaningful_paint/index.md?plain=1 "Folder: en-us/glossary/first_meaningful_paint \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_meaningful_paint&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst_meaningful_paint%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_meaningful_paint%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst_meaningful_paint%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: first-paint-fp-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/First_paint-0.md
category: reference
title: First Paint (FP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_paint
date_saved: 2026-05-05T05:31:43.219572+00:00
instance: kb-cron
parent: first-paint-fp-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/First_paint#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/First_paint#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: first-paint-fp-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/First_paint-1.md
category: reference
title: First Paint (FP) - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/First_paint
date_saved: 2026-05-05T05:31:43.219572+00:00
instance: kb-cron
parent: first-paint-fp-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Oct 30, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/First_paint/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/first_paint/index.md?plain=1 "Folder: en-us/glossary/first_paint \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_paint&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffirst_paint%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFirst_paint%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffirst_paint%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2d78abb3e793352e24e976ce0e68c08d817bd7f3%0A*+Document+last+modified%3A+2025-10-30T16%3A59%3A53.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: flex-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex-0.md
category: reference
title: Flex - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex
date_saved: 2026-05-05T05:31:45.904848+00:00
instance: kb-cron
parent: flex-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Flex#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Flex#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: flex-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex-1.md
category: reference
title: Flex - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex
date_saved: 2026-05-05T05:31:45.904848+00:00
instance: kb-cron
parent: flex-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Dec 18, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Flex/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/flex/index.md?plain=1 "Folder: en-us/glossary/flex \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fflex%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fflex%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F5ba55a6939c0aaf988fc4d34ad7e51c52373a2a6%0A*+Document+last+modified%3A+2025-12-18T13%3A38%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: flex-container-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex_Container-0.md
category: reference
title: Flex container - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex_Container
date_saved: 2026-05-05T05:31:48.447550+00:00
instance: kb-cron
parent: flex-container-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Container#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Container#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: flex-container-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex_Container-1.md
category: reference
title: Flex container - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex_Container
date_saved: 2026-05-05T05:31:48.447550+00:00
instance: kb-cron
parent: flex-container-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Container/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/flex_container/index.md?plain=1 "Folder: en-us/glossary/flex_container \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex_Container&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fflex_container%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex_Container%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fflex_container%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: flex-item-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex_Item-0.md
category: reference
title: Flex item - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex_Item
date_saved: 2026-05-05T05:31:50.905777+00:00
instance: kb-cron
parent: flex-item-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Item#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Item#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: flex-item-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Flex_Item-1.md
category: reference
title: Flex item - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flex_Item
date_saved: 2026-05-05T05:31:50.905777+00:00
instance: kb-cron
parent: flex-item-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Flex_Item/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/flex_item/index.md?plain=1 "Folder: en-us/glossary/flex_item \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex_Item&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fflex_item%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlex_Item%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fflex_item%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: flexbox-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Flexbox-0.md
category: reference
title: Flexbox - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flexbox
date_saved: 2026-05-05T05:31:53.301699+00:00
instance: kb-cron
parent: flexbox-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Flexbox#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Flexbox#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: flexbox-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Flexbox-1.md
category: reference
title: Flexbox - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flexbox
date_saved: 2026-05-05T05:31:53.301699+00:00
instance: kb-cron
parent: flexbox-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Flexbox/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/flexbox/index.md?plain=1 "Folder: en-us/glossary/flexbox \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlexbox&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fflexbox%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlexbox%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fflexbox%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: flow-relative-values-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values-0.md
category: reference
title: Flow relative values - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values
date_saved: 2026-05-05T05:31:55.891919+00:00
instance: kb-cron
parent: flow-relative-values-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: flow-relative-values-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values-1.md
category: reference
title: Flow relative values - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values
date_saved: 2026-05-05T05:31:55.891919+00:00
instance: kb-cron
parent: flow-relative-values-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Flow_relative_values/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/flow_relative_values/index.md?plain=1 "Folder: en-us/glossary/flow_relative_values \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlow_relative_values&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fflow_relative_values%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFlow_relative_values%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fflow_relative_values%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: forbidden-request-header-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header-0.md
category: reference
title: Forbidden request header - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header
date_saved: 2026-05-05T05:31:58.447440+00:00
instance: kb-cron
parent: forbidden-request-header-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: forbidden-request-header-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header-1.md
category: reference
title: Forbidden request header - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header
date_saved: 2026-05-05T05:31:58.447440+00:00
instance: kb-cron
parent: forbidden-request-header-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 17, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_request_header/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/forbidden_request_header/index.md?plain=1 "Folder: en-us/glossary/forbidden_request_header \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FForbidden_request_header&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fforbidden_request_header%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FForbidden_request_header%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fforbidden_request_header%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2Fa8a430360e652306ae0b2d97388da9501671d2fb%0A*+Document+last+modified%3A+2025-11-17T19%3A14%3A42.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: forbidden-response-header-name-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name-0.md
category: reference
title: Forbidden response header name - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name
date_saved: 2026-05-05T05:32:01.087304+00:00
instance: kb-cron
parent: forbidden-response-header-name-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: forbidden-response-header-name-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name-1.md
category: reference
title: Forbidden response header name - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name
date_saved: 2026-05-05T05:32:01.087304+00:00
instance: kb-cron
parent: forbidden-response-header-name-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Forbidden_response_header_name/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/forbidden_response_header_name/index.md?plain=1 "Folder: en-us/glossary/forbidden_response_header_name \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FForbidden_response_header_name&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fforbidden_response_header_name%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FForbidden_response_header_name%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fforbidden_response_header_name%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fork-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fork-0.md
category: reference
title: Fork - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fork
date_saved: 2026-05-05T05:32:03.709960+00:00
instance: kb-cron
parent: fork-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fork#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fork#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fork-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fork-1.md
category: reference
title: Fork - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fork
date_saved: 2026-05-05T05:32:03.709960+00:00
instance: kb-cron
parent: fork-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Apr 14, 2026 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fork/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fork/index.md?plain=1 "Folder: en-us/glossary/fork \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFork&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffork%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFork%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffork%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2Fef78a9a3336c884fb3587e4ff833e64704296f01%0A*+Document+last+modified%3A+2026-04-14T01%3A23%3A02.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fragmentainer-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fragmentainer-0.md
category: reference
title: Fragmentainer - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fragmentainer
date_saved: 2026-05-05T05:32:06.085615+00:00
instance: kb-cron
parent: fragmentainer-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fragmentainer#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fragmentainer#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fragmentainer-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fragmentainer-1.md
category: reference
title: Fragmentainer - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fragmentainer
date_saved: 2026-05-05T05:32:06.085615+00:00
instance: kb-cron
parent: fragmentainer-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 7, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fragmentainer/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fragmentainer/index.md?plain=1 "Folder: en-us/glossary/fragmentainer \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFragmentainer&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffragmentainer%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFragmentainer%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffragmentainer%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F85fccefc8066bd49af4ddafc12c77f35265c7e2d%0A*+Document+last+modified%3A+2025-11-07T15%3A58%3A06.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: function-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Function-0.md
category: reference
title: Function - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Function
date_saved: 2026-05-05T05:32:08.608917+00:00
instance: kb-cron
parent: function-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Function#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Function#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: function-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Function-1.md
category: reference
title: Function - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Function
date_saved: 2026-05-05T05:32:08.608917+00:00
instance: kb-cron
parent: function-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Nov 13, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Function/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/function/index.md?plain=1 "Folder: en-us/glossary/function \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFunction&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffunction%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFunction%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffunction%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F0c81cbce5f95a0be935724bcd936f5592774eb3a%0A*+Document+last+modified%3A+2025-11-13T20%3A10%3A50.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: fuzz-testing-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/Fuzzing-0.md
category: reference
title: Fuzz testing - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing
date_saved: 2026-05-05T05:32:11.960699+00:00
instance: kb-cron
parent: fuzz-testing-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: fuzz-testing-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/Fuzzing-1.md
category: reference
title: Fuzz testing - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing
date_saved: 2026-05-05T05:32:11.960699+00:00
instance: kb-cron
parent: fuzz-testing-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/Fuzzing/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/fuzzing/index.md?plain=1 "Folder: en-us/glossary/fuzzing \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFuzzing&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Ffuzzing%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FFuzzing%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Ffuzzing%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: gif-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/GIF-0.md
category: reference
title: GIF - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/GIF
date_saved: 2026-05-05T05:32:14.805107+00:00
instance: kb-cron
parent: gif-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/GIF#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/GIF#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


id: gif-glossary-mdn-20260505-1
file: data/developer.mozilla.org/en-US/docs/Glossary/GIF-1.md
category: reference
title: GIF - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/GIF
date_saved: 2026-05-05T05:32:14.805107+00:00
instance: kb-cron
parent: gif-glossary-mdn-20260505-0
summary:
## Help improve MDN [Learn how to contribute](https://developer.mozilla.org/en-US/docs/MDN/Community/Getting_started) This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/GIF/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/gif/index.md?plain=1 "Folder: en-us/glossary/gif \(Opens in a new tab\)") • [Report a problem with this content](https://github.com/mdn/content/issues/new?template=page-report.yml&mdn-url=https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FGIF&metadata=%3C%21--+Do+not+make+changes+below+this+line+--%3E%0A%3Cdetails%3E%0A%3Csummary%3EPage+report+details%3C%2Fsummary%3E%0A%0A*+Folder%3A+%60en-us%2Fglossary%2Fgif%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FGIF%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fgif%2Findex.md%0A*+Last+commit%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fcommit%2F2547f622337d6cbf8c3794776b17ed377d6aad57%0A*+Document+last+modified%3A+2025-07-11T14%3A45%3A59.000Z%0A%0A%3C%2Fdetails%3E "This will take you to GitHub to file a new issue.") 1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary) 2. 1. [Abstraction](https://developer.mozilla.org/en-US/docs/Glossary/Abstraction) 2. [Accent](https://developer.mozilla.org/en-US/docs/Glossary/Accent) 3. [Accessibility](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility) 4. [Accessibility tree](https://developer.mozilla.org/en-US/docs/Glossary/Accessibility_tree) 5. [Accessible description](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_description) 6. [Accessible name](https://developer.mozilla.org/en-US/docs/Glossary/Accessible_name) 7. [Adobe Flash](https://developer.mozilla.org/en-US/docs/Glossary/Adobe_Flash) 8. [Advance measure](https://developer.mozilla.org/en-US/docs/Glossary/Advance_measure) 9. [Ajax](https://developer.mozilla.org/en-US/docs/Glossary/AJAX) 10. [Algorithm](https://developer.mozilla.org/en-US/docs/Glossary/Algorithm) 11. [Alignment container](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Container) 12. [Alignment subject](https://developer.mozilla.org/en-US/docs/Glossary/Alignment_Subject) 13. [Alpha (alpha channel)](https://developer.mozilla.org/en-US/docs/Glossary/Alpha) 14. [ALPN](https://developer.mozilla.org/en-US/docs/Glossary/ALPN) 15. [API](https://developer.mozilla.org/en-US/docs/Glossary/API) 16. [Apple Safari](https://developer.mozilla.org/en-US/docs/Glossary/Apple_Safari) 17. [Application context](https://developer.mozilla.org/en-US/docs/Glossary/Application_context) 18. [Argument](https://developer.mozilla.org/en-US/docs/Glossary/Argument) 19. [ARIA](https://developer.mozilla.org/en-US/docs/Glossary/ARIA) 20. [ARPA](https://developer.mozilla.org/en-US/docs/Glossary/ARPA) 21. [ARPANET](https://developer.mozilla.org/en-US/docs/Glossary/Arpanet) 22. [Array](https://developer.mozilla.org/en-US/docs/Glossary/Array) 23. [ASCII](https://developer.mozilla.org/en-US/docs/Glossary/ASCII) 24. [Aspect ratio](https://developer.mozilla.org/en-US/docs/Glossary/Aspect_ratio) 25. [Asynchronous](https://developer.mozilla.org/en-US/docs/Glossary/Asynchronous) 26. [ATAG](https://developer.mozilla.org/en-US/docs/Glossary/ATAG) 27. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute) 28. [Authentication](https://developer.mozilla.org/en-US/docs/Glossary/Authentication) 29. [Authenticator](https://developer.mozilla.org/en-US/docs/Glossary/Authenticator) 30. [Bandwidth](https://developer.mozilla.org/en-US/docs/Glossary/Bandwidth) 31. [Base64](https://developer.mozilla.org/en-US/docs/Glossary/Base64) 32. [Baseline](https://developer.mozilla.org/en-US/docs/Glossary/Baseline) 1. [Baseline (compatibility)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Compatibility) 2. [Baseline (typography)](https://developer.mozilla.org/en-US/docs/Glossary/Baseline/Typography) 33. [BCP 47 language tag](https://developer.mozilla.org/en-US/docs/Glossary/BCP_47_language_tag) 34. [Beacon](https://developer.mozilla.org/en-US/docs/Glossary/Beacon) 35. [Bézier curve](https://developer.mozilla.org/en-US/docs/Glossary/Bezier_curve) 36. [bfcache](https://developer.mozilla.org/en-US/docs/Glossary/bfcache) 37. [BiDi](https://developer.mozilla.org/en-US/docs/Glossary/BiDi) 38. [BigInt](https://developer.mozilla.org/en-US/docs/Glossary/BigInt) 39. [Binding](https://developer.mozilla.org/en-US/docs/Glossary/Binding) 40. [Bitwise flags](https://developer.mozilla.org/en-US/docs/Glossary/Bitwise_flags) 41. [Blink](https://developer.mozilla.org/en-US/docs/Glossary/Blink) 42. [blink element (<blink> tag)](https://developer.mozilla.org/en-US/docs/Glossary/blink_element) 43. [Block](https://developer.mozilla.org/en-US/docs/Glossary/Block) 1. [Block (CSS)](https://developer.mozilla.org/en-US/docs/Glossary/Block/CSS) 2. [Block (scripting)](https://developer.mozilla.org/en-US/docs/Glossary/Block/Scripting) 44. [Block cipher mode of operation](https://developer.mozilla.org/en-US/docs/Glossary/Block_cipher_mode_of_operation) 45. [Block-level content](https://developer.mozilla.org/en-US/docs/Glossary/Block-level_content) 46. [Boolean](https://developer.mozilla.org/en-US/docs/Glossary/Boolean) 1. [Boolean (JavaScript)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/JavaScript) 2. [Boolean attribute (ARIA)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/ARIA) 3. [Boolean attribute (HTML)](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) 47. [Bounding box](https://developer.mozilla.org/en-US/docs/Glossary/Bounding_box) 48. [Breadcrumb](https://developer.mozilla.org/en-US/docs/Glossary/Breadcrumb) 49. [Brotli


id: gpl-glossary-mdn-20260505-0
file: data/developer.mozilla.org/en-US/docs/Glossary/GPL-0.md
category: reference
title: GPL - Glossary | MDN
tags: web, html, css, javascript, documentation
source_url: https://developer.mozilla.org/en-US/docs/Glossary/GPL
date_saved: 2026-05-05T05:32:17.363584+00:00
instance: kb-cron
parent: gpl-glossary-mdn-20260505-0
summary:
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/GPL#content) * [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/GPL#search) [ MDN ](https://developer.mozilla.org/en-US/) HTML [HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML) HTML reference * [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements) * [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes) * [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references") HTML guides * [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images) * [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet) * [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats) * [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides") Markup languages * [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG) * [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML) * [XML](https://developer.mozilla.org/en-US/docs/Web/XML) CSS [CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS) CSS reference * [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties) * [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors) * [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules) * [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references") CSS guides * [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction) * [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using) * [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts) * [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides") Layout cookbook * [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts) * [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element) * [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card) * [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook) JavaScriptJS [JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript) JS reference * [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects) * [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators) * [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements) * [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references") JS guides * [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling) * [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration) * [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects) * [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes) * [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides") Web APIs [Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API) Web API reference * [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API) * [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) * [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API) * [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API) * [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API) * [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API) * [See all…](https://developer.mozilla.org/en-US/docs/Web/API


