AJAX is a technique for creating fast and dynamic web pages.
AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.
Classic web pages, (which do not use AJAX) must reload the entire page if the content should change.
This is pretty much the most striking benefit behind why several developers and webmasters are switching to AJAX for their websites. AJAX allows easier and quicker interaction between user and website as pages are not reloaded for content to be displayed.
AJAX applications on websites can be built to allow easier navigation to users in comparison to using the traditional back and forward button on a browser.
With AJAX, several multi purpose applications and features can be handled using a single web page, avoiding the need for clutter with several web pages.
Backed by reputed brands
Another assuring reason to use AJAX on your websites is the fact that several complex web applications are handled using AJAX, Google Maps is the most impressive and obvious example, other powerful, popular scripts such as the vBulletin forum software has also incorporated AJAX into their latest version.
The back and refresh button are rendered useless
With AJAX, as all functions are loaded on a dynamic page without the page being reloaded, clicking the back or refresh button would take you to an entirely different web page or to the beginning of what your dynamic web page was processing.