JavaScript，一种直译式编程语言，是一种动态类型、基于原型的语言，内置支持类别。它的解释器被称为JavaScript引擎，为浏览器的一部分，广泛用于客户端的脚本语言，最早是在HTML网页上使用，用来给HTML网页增加动态功能。然而现在JavaScript也可被用于网络服务器，如Node.js。

在1995年时，由网景公司的布兰登·艾克，在网景领航员浏览器上首次设计实作而成。因为网景公司与升阳公司的行销合作，加上网景公司管理层希望它外观看起来像Java，因此取名为JavaScript。但实际上它的语义与Self及Scheme较为接近。

JavaScript (/ˈdʒɑːvəˌskrɪpt/) is a high-level, dynamic, untyped, and interpreted programming language. It has been standardized in the ECMAScript language specification. Alongside HTML and CSS, it is one of the three core technologies of World Wide Web content production; the majority of websites employ it and it is supported by all modern Web browsers without plug-ins. JavaScript is prototype-based with first-class functions, making it a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles. It has an API for working with text, arrays, dates and regular expressions, but does not include any I/O, such as networking, storage, or graphics facilities, relying for these upon the host environment in which it is embedded.