Ajax

What is AJAX?
AJAX stands for Asynchronous JavaScript and XML. AJAX is a new technique for creating better, faster, and more interactive web applications with the help of XML, HTML, CSS, and Java Script.

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 is based on the following open standards:
    --     Browser-based presentation using HTML and Cascading Style Sheets (CSS).
    --     Data is stored in XML format and fetched from the server.
    --     Behind-the-scenes data fetches using XMLHttpRequest objects in the browser.
    --    JavaScript to make everything happen.

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.

What AJAX Do..??
-- Update a web page without reloading the page
-- Request data from a server - after the page has loaded
-- Receive data from a server - after the page has loaded
-- Send data to a server - in the background