---
title: "HTML5 - Glossary | MDN"
chunk: 2/3
source: "https://developer.mozilla.org/en-US/docs/Glossary/HTML5"
category: "reference"
tags: "web, html, css, javascript, documentation"
date_saved: "2026-05-05T05:33:28.851037+00:00"
instance: "kb-cron"
---
## Help improve MDN
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This page was last modified on Jul 11, 2025 by [MDN contributors](https://developer.mozilla.org/en-US/docs/Glossary/HTML5/contributors.txt). [View this page on GitHub](https://github.com/mdn/content/blob/main/files/en-us/glossary/html5/index.md?plain=1 "Folder: en-us/glossary/html5 \(Opens in a new tab\)") • [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%2FHTML5&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%2Fhtml5%60%0A*+MDN+URL%3A+https%3A%2F%2Fdeveloper.mozilla.org%2Fen-US%2Fdocs%2FGlossary%2FHTML5%0A*+GitHub+URL%3A+https%3A%2F%2Fgithub.com%2Fmdn%2Fcontent%2Fblob%2Fmain%2Ffiles%2Fen-us%2Fglossary%2Fhtml5%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 (