AJAX (Asynchronous JavaScript and XML) is a rapidly emerging programming technique that attracts lots of attention nowadays and is a model of web development, designed for creating interactive web applications. AJAX is a technique for creating fast and dynamic web pages.
AJAX is the art of exchanging data with a server, and updating parts of a web page – without reloading the whole page. 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.