AJAX

AJAX = Asynchronous JavaScript And XML.

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 webpage, without reloading the whole page.

1. An event occurs in a web page (the page is loaded, a button is clicked)
2. An XMLHttpRequest object is created by  JavaScript
3. The XMLHttpRequest object sends a  request to a web server
4. The server processes the request
5. The server sends a response back to the web page
6. The response is read by JavaScript
7. Proper action (like page update) is performed by JavaScript








AJAX is not a programming language.

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