AJAX

AJAX is short for Asynchronous JavaScript and XML. AJAX is the art of exchanging data with a server, a programming practice of combining HTML, CSS, JavaScript, the DOM, and the XMLHttpRequest object to build complex webpages that update dynamically without reloading the whole page.

Web applications can send data to and receive it from a server in the background without interfering with the display and behavior of the existing page.

Ajax is a group of technologies. HTML and CSS can be used in combination to mark up and style information. The DOM is accessed with JavaScript to dynamically display and allow the user to interact with the information presented. JavaScript and the XMLHttpRequest object provide a method for exchanging data in a background between browser and server to avoid full page reloads.

The following technologies are involved in AJAX:

1. HTML (or XHTML) and CSS for presentation.
2. The Document Object Model (DOM) for dynamic display of and interaction with data.
3. XML for the interchange of data, and XSLT for its manipulation.
4. The XMLHttpRequest object for asynchronous communication.
5. JavaScript to bring these technologies together.