JavaScript is a client side web programming language. This means that it interacts with the user after the web page has already loaded. Developers use JavaScript control dynamic content and add interactivity to web pages. The possibilities are virtually endless but a few common uses are validating forms, animations, dynamic pages, setting cookies, and web games.

The programming language was invented by Netscape in the early days of the web and has evolved significantly since that point. It was originally called LiveScript but was renamed hoping to gain some of the attention that Java (not to be confused with JavaScript) was getting at the time.