AJAX - A Closer Look

AJAX stands for Asynchronous JavaScript and XML. AJAX is a new technique for creating better, faster, and more interactive web applications with the help of XML, HTML, CSS and Java Script.

Conventional web application trasmit information to and from the sever using synchronous requests. This means you fill out a form, hit submit, and get directed to a new page with new information from the server.

With AJAX when submit is pressed, JavaScript will make a request to the server, interpret the results and update the current screen. In the purest sense, the user would never know that anything was even transmitted to the server.

Technologies Used in AJAX

JavaScript

• Loosely typed scripting language
• JavaScript function is called when an event in a page occurs
• Glue for the whole AJAX operation

DOM

• API for accessing and manipulating structured documents
• Represents the structure of XML and HTML documents

CSS

• Allows for a clear separation of the presentation style from the content and may be changed programmatically by JavaScript

XMLHttpRequest

• JavaScript object that performs asynchrous interaction with the server