AJAX, is a new looking angle for web applications. Abbr. Asynchronous JavaScript and XML (AJAX). As you can understand from its name it's not related with a bleaching liquid brand in any way.
In fact AJAX, is not a new technology like it's known. I always advocate the thesis of AJAX is a tech. But seems like Gmail.com user interface that has totally been prepared with AJAX is found attractive by most of web designers so AJAX made a big explosion. Recently Yahoo.com has also joined this glut. Right now many web designers are trying to learn AJAX to be able to apply this new technique to their websites.

By using AJAX, connecting to web server without refreshes is possible. Think a web form, there is a textfield for an e-mail address. And a button for submitting the form. At classic web applications when you click on button browser redirects you to another URL address and there necessaried controls are being made and saved to database, and for last you see the result message. In fact that kind of applications are never useful for website owners; because new control and saving page needs some of server resources. And it means an addition to hosting outcome. But AJAX technique is completely wiping up the new page creating process. Just one data connection happens between browser and web server. Also that data amount is an extremely little value. I guess there is no need to say AJAX applications are both good for website owners and Internet users. Additionally web sites made by using AJAX are gorgeous looking and simple to use applications.

So why aren't there enough amount of web pages prepared with AJAX ? In fact this question's answer is very simple. Preparing web pages with AJAX takes long and in addition to this, users can block JavaScript codes from the settings of their browsers. In this situation web page that was created with AJAX technique will appear an error and not work. Also, the developers of web browsers haven't set a standard yet for JavaScript and its objects. Because of the reasons like these AJAX's developing is proceeding very slowly.