AJAX (Asynchronous JavaScript and XML / XMLHttpRequest) is a web development technique used for creating interactive web applications. The word 'AJAX' is an acronym for Asynchronous JavaScript and XML / XMLHttpRequest. Like all acronyms in the English language, it should be written with all capital letters, something a lot of bloggers, etc. forget.
The intent of AJAX is to make web pages feel more responsive to the user. It accomplishes this by exchanging small amounts of data with the server it is interacting with while the user is able to conduct other business on the website at the same time. With this Asynchronous communication taking place 'behind the scenes', the whole web page doesn't have to be reloaded each time the user submits some data, just the new/modified data itself.
Overall, this increases the page's interactivity, speed, functionality, and usability when done correctly. AJAX uses JavaScript as the programming language for its function calls. Data retrieved using this technique is commonly formatted using XML. [more]
