JavaScript is a lightweight object-based scripting language created by Netscape Communications Corporation for developing Internet applications. JavaScript is lightweight in that there isn't a great deal to learn and you can be productive with it very quickly, in contrast to much more complex languages such as Java. As a scripting language, JavaScript is meant to tell an application what to do. Unlike languages used to create applications, it cannot do anything without the application. You can develop server applications or client applications with JavaScript. You can embed JavaScript statements in Web pages, which are written in HTML. JavaScript is an extension to HTML that lets you create more sophisticated Web pages than you ever could with HTML alone.