JavaScript is basically a lightweight client-side scripting language for web pages. It was written by Brendan Eich at Netscape in May 1995, in a span of just 10 days, and was first implemented in Netscape Navigator 2.0 browser which appeared in March 1996.

Today, JavaScript has moved beyond the browser environment. It is now used for server-side scripting, in game development, to program microcontrollers, and for adding interactivity to PDF documents. It is also the default language for the GNOME Shell.

JavaScript is based on the ECMAScript standard. The current version of ECMAScript language is ECMAScript 2015 (6th Edition), commonly known as "ES6."