JavaScript is a simple programming language used to make web pages more interactive. Once known as LiveScript, JavaScript's name was changed as part of a marketing deal between Netscape and Sun. People talk about Java and JavaScript as if they were interchangeable, but they are completely different things. You do not need a Java runtime environment in order to use a JavaScript-enabled web page.

JavaScript can be used with the Document Object Model (DOM) to create powerful web applications like Google's GMail service. GMail lets the user browse through their email without constantly waiting for the web server every time they click. JavaScript is now able to do many jobs that formerly required Java or Flash. Since JavaScript doesn’t require plugins, I recommend JavaScript instead of Flash or Java wherever possible, with a fallback plain-HTML option for users with older browsers or handheld devices. ...