The Basic AJAX Principles

Dec 17, 2007 18:21 GMT  ·  By

AJAX is a web development technique (not a new programming language) that allows you to create faster and more user friendly web applications. AJAX stands for Asynchronous JavaScript And XML. It changes the way a web page is processed on client side using server side information.

Practically, AJAX combines many existing web technologies, such as Javascript, CSS, DOM, PHP and more. Javascript comunicates directly with the server through XMLHttpRequest API and this way the information exchanged between client and server is "invisible", because the content of the page will update for a given user action without the need to reload that page.

The asynchronous behaviour of Javascript resides in the fact that data requested from server is loaded on client side without generation of interferences with the actual page display. The applications made with AJAX will not depend on web server software and are fast because the time nedeed to exchange certain quantity of information with the server is lower than the time necessary to reload the whole page. As a consequence the application response time to users' requests are decreased with AJAX.

AJAX has many other advantages. It can be employed to create more user friendly forms which could be validated in real time, rich web applications with appearance and functionality similar to desktop applications and more. The applications made with AJAX can be used on any operating system in any modern web browser that provides support for XMLHttpRequest object. Generally the quantity of information exchanged with a web server is small.

Due to the small quantity of information downloaded from webserver in order to update only a part of a webpage, without reloading it, the bandwidth consumption is reduced while the page loading time is optimized. In order to begin the development of web applications with AJAX, you do not have to learn new programming languages, because it is based on actual web standard programming languages.