AJAX (Asynchronous JavaScript and XML) a new technology word that is forwarding the web towards a way that might never been thought. AJAX is filling the gap that exists

between the server and the client’s machine. You can experience the AJAX based web applications as using something installed on to your desktop. Flickering of browser, Page Reload, Waiting for response from the server are now getting the talk of past.

Some of the characteristics of AJAX applications include:

Continuous Feel: As traditional web application, may let you fill the forms than post it, and wait for the response from the server, that may be irretating but here it's not the case with applications enabled with AJAX. They will provide the interface as the user is working on window applciation however the applciation is hosted remotely(all the process is going on in the server) and also the tasks are splitted into small threads as per the user requests(however threads are not implemented but through functions).

Real-Time Updates: If you will go through the spreadsheets provided by the Google, you will find how the web is getting rich in terms of responsiveness. Its all based on AJAX and the updates are done on the server in the real time.

Language Neutrality - The most important characteristic of AJAX is that it can work in combination with any language because of its implementation. As it includes Java Script and XML that are supported by any present technology, the term AJAX also does the same. And it makes it so popular.