AJAX is an acronym that stands for Asynchronous JavaScript and XML.
AJAX is not a programming language.AJAX just uses a combination of:
1. A browser built-in XMLHttpRequest object (to request data from a web server)
2. JavaScript and HTML DOM (to display or use the data)
and it describes a set of development techniques used for building websites and web applications. AJAX’s core function is to update web content asynchronously, meaning a user’s web browser doesn’t need to reload an entire web page when only a small portion of content on the page needs to change.