What's AJAX?

Asynchronous JavaScript And XML, or its acronym Ajax (Pronounced A-JAX), is a Web development technique for creating interactive web applications.

The intent is to shift a great deal of interaction to the Web surfer's computer, exchanging data with the server behind the scenes, so that the entire Web page does not have to be reloaded each time the user makes a change. This is meant to increase the Web page's interactivity, speed, and usability.