Ajax stands for Asynchronous java script and XML. Itís not a new technology rather it is a concept that combines the several programming tool that includes Java script, dynamic HTML, Extensive Markup Language (XML), Cascading style sheets (CSS), Document Object Model (DOM) and the Microsoft Object, XMLHttpRequest. Ajax is a client side script that communicates with server without the requirement of complete page refresh. This means Ajax allows immediate updating of content on webpage as compared to http requests in which users need to wait for the complete loading of page. This provides more functionality in the websites. Various renowned web applications like Gmail, Outlook Web Access and Google Maps use Ajax concept. Ajax applications do not require plug-in, rather it works directly with web browsers. Ajax applications use an engine that works as mediator between browser and server. Userís browser loads Ajax engine that displays the userís required page.