Introduction To Ajax

Ajax (Asynchronous JavaScript and XML) is used to create interactive web applications. Ajax can make web pages feel more responsive by exchanging small amounts of data with the server behind the scenes so that the entire page does not have to be reloaded each time there is a change. Ajax is not a programming language or a unique technology -- Ajax uses a combination of existing technologies:

• HTML or XHTML and CSS for marking up and styling information.
• The Document Object Model (DOM) accessed with a client-side scripting language such as JavaScript to dynamically display and interact with the information presented.
• The XMLHttpRequest object to exchange data asynchronously with the web server.
• A format for transferring data between the server and client. This can be HTML, PHP, XML, etc. \