The web developer’s arsenal for creating a content rich and dynamic website is JavaScript. In short, JavaScript is a scripting language that runs on the browser and can dynamically change the content that the user sees on the webpage. JavaScript can be used to perform client side checking of the data that a user submits to a website, modify the user interface according to the user’s preferences or even create new web pages without querying the website server.

JavaScript is an object oriented scripting language and an interpreter is built-in in most modern browsers. Proficiency in JavaScript allows the developer to create highly interactive websites while keeping website traffic to a minimum because some of the data processing is being done on the browser. For example, it is possible for the website application to just pass data between the browser and server while the JavaScript code performs the formatting based on the data and user preferences.

JavaScript, in spite of the name similarity, is not the same as the Java programming language. JavaScript runs only in browsers and is usually an integral part of the web application. Java, however, may be imbedded in a web application but it runs as an applet or a small application that is independent of the browser. JavaScript is run by the browser itself.

At present, a lot of the highly interactive websites like Facebook and Gmail, heavily use JavaScript in a protocol called Ajax. We will talk about Ajax next week. It is a protocol that is required to build highly interactive but efficient websites. It is based on the JavaScript scripting language.