AJAX = Asynchronous JavaScript And XML.

AJAX is not a programming language. AJAX just uses a combination of: A browser built-in XMLHttpRequest object (to request data from a web server) JavaScript and HTML DOM (to display or use the data) AJAX allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.