---
title: "JavaScript - Glossary | MDN"
chunk: 1/3
source: "https://developer.mozilla.org/en-US/docs/Glossary/JavaScript"
category: "reference"
tags: "web, html, css, javascript, documentation"
date_saved: "2026-05-05T05:35:55.894160+00:00"
instance: "kb-cron"
---

  * [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript#content)
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[ 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 "See all Web API guides")

Web API guides
    
  * [Using the Web animation API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Animations_API/Using_the_Web_Animations_API)
  * [Using the Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch)
  * [Working with the History API](https://developer.mozilla.org/en-US/docs/Web/API/History_API/Working_with_the_History_API)
  * [Using the Web speech API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Speech_API/Using_the_Web_Speech_API)
  * [Using web workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers)

All
[All web technology](https://developer.mozilla.org/en-US/docs/Web) 

Technologies
    
  * [Accessibility](https://developer.mozilla.org/en-US/docs/Web/Accessibility)
  * [HTTP](https://developer.mozilla.org/en-US/docs/Web/HTTP)
  * [URI](https://developer.mozilla.org/en-US/docs/Web/URI)
  * [Web extensions](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions)
  * [WebAssembly](https://developer.mozilla.org/en-US/docs/WebAssembly)
  * [WebDriver](https://developer.mozilla.org/en-US/docs/Web/WebDriver)
  * [See all…](https://developer.mozilla.org/en-US/docs/Web "See all web technology references")

Topics
    
  * [Media](https://developer.mozilla.org/en-US/docs/Web/Media)
  * [Performance](https://developer.mozilla.org/en-US/docs/Web/Performance)
  * [Privacy](https://developer.mozilla.org/en-US/docs/Web/Privacy)
  * [Security](https://developer.mozilla.org/en-US/docs/Web/Security)
  * [Progressive web apps](https://developer.mozilla.org/en-US/docs/Web/Progressive_web_apps)

Learn
[Learn web development](https://developer.mozilla.org/en-US/docs/Learn_web_development) 

Frontend developer course
    
  * [Getting started modules](https://developer.mozilla.org/en-US/docs/Learn_web_development/Getting_started)
  * [Core modules](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core)
  * [MDN Curriculum](https://developer.mozilla.org/en-US/curriculum/)
  * [Check out the video course from Scrimba, our partner](https://scrimba.com/frontend-path-c0j?via=mdn-learn-navbar)

Learn HTML
    
  * [Structuring content with HTML module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Structuring_content)

Learn CSS
    
  * [CSS styling basics module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics)
  * [CSS layout module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/CSS_layout)

Learn JavaScript
    
  * [Dynamic scripting with JavaScript module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Scripting)

Tools
Discover our tools 
  * [Playground](https://developer.mozilla.org/en-US/play)
  * [HTTP Observatory](https://developer.mozilla.org/en-US/observatory)

  * [Border-image generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Border-image_generator)
  * [Border-radius generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Border-radius_generator)
  * [Box-shadow generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Box-shadow_generator)
  * [Color format converter](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Color_format_converter)
  * [Color mixer](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Color_mixer)
  * [Shape generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Shapes/Shape_generator)

About
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[Blog](https://developer.mozilla.org/en-US/blog/)
  1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary)
  2. [JavaScript](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript)

# JavaScript
JavaScript (or "JS") is a programming language used most often for dynamic client-side scripts on webpages, but it is also often used on the [server](https://developer.mozilla.org/en-US/docs/Glossary/Server)-side, using a runtime such as [Node.js](https://developer.mozilla.org/en-US/docs/Glossary/Node.js), [Deno](https://developer.mozilla.org/en-US/docs/Glossary/Deno), and [Bun](https://bun.com/).
JavaScript **should not** be confused with the [Java programming language](https://en.wikipedia.org/wiki/Java_\(programming_language\)). Although _"Java"_ and _"JavaScript"_ are trademarks (or registered trademarks) of Oracle in the U.S. and other countries, the two programming languages are significantly different in their syntax, semantics, and use cases.
JavaScript is primarily used in the browser, enabling developers to manipulate webpage content through the [DOM](https://developer.mozilla.org/en-US/docs/Glossary/DOM), retrieve content from servers using the [`fetch()`](https://developer.mozilla.org/en-US/docs/Web/API/Window/fetch "fetch\(\)") API, store complex data using [IndexedDB](https://developer.mozilla.org/en-US/docs/Glossary/IndexedDB), draw graphics with [canvas](https://developer.mozilla.org/en-US/docs/Glossary/Canvas), interact with the device running the browser through various [APIs](https://developer.mozilla.org/en-US/docs/Glossary/API), and more. JavaScript is one of the world's most commonly-used languages, owing to the recent growth and performance improvement of [APIs](https://developer.mozilla.org/en-US/docs/Glossary/API) available in browsers.
## In this article
  * [Origins and History](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript#origins_and_history)
  * [See also](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript#see_also)

##  [Origins and History](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript#origins_and_history)
Conceived as a server-side language by Brendan Eich (then employed by the Netscape Corporation), JavaScript soon came to Netscape Navigator 2.0 in September 1995. JavaScript enjoyed immediate success and [Internet Explorer 3.0](https://developer.mozilla.org/en-US/docs/Glossary/Microsoft_Internet_Explorer) introduced JavaScript support under the name JScript in August 1996.
In November 1996, Netscape began working with Ecma International to make JavaScript an industry standard. Since then, the standardized JavaScript is called ECMAScript and specified under ECMA-262. The standard is constantly updated and implemented (a _living standard_).
Recently, JavaScript's popularity has expanded even further through the successful [Node.js](https://nodejs.org/en) platform—the most popular cross-platform JavaScript runtime environment outside the browser. Node.js - built using [Chrome's V8 JavaScript Engine](https://en.wikipedia.org/wiki/V8_\(JavaScript_engine\)) - allows developers to use JavaScript as a scripting language to automate things on a computer and build fully functional [HTTP](https://developer.mozilla.org/en-US/docs/Glossary/HTTP) and [WebSockets](https://developer.mozilla.org/en-US/docs/Glossary/WebSockets) servers.
##  [See also](https://developer.mozilla.org/en-US/docs/Glossary/JavaScript#see_also)
  * [JavaScript](https://en.wikipedia.org/wiki/JavaScript) on Wikipedia
  * The [JavaScript Guide](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide) on MDN
  * [The "javascripting" workshop on NodeSchool](https://nodeschool.io/#workshoppers)
  * [The JavaScript course on codecademy.com](https://www.codecademy.com/catalog/language/javascript)
  * [The latest ECMAScript standard](https://ecma-international.org/publications-and-standards/standards/ecma-262/)
  * The [JavaScript reference](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference) on MDN
  * [The _Eloquent JavaScript_ book](https://eloquentjavascript.net/)