In the classic web application model, a user has to wait every time an Http request is sent to the server for processing an HTML web page to the client. In the Ajax application model, an Ajax engine is introduced between the user and the server which eliminates the need of waiting for the server’s response. The engine is loaded every time by the browser whenever a session is initiated. It allows asynchronous communication between the user and the application. As a result the speed, interactivity and usability of the web pages are greatly increased. Using Ajax, the user fetches small chunks of data from the server behind the scene and not the complete set of information. Simple processes such as data validation, data editing memory are handled by the Ajax engine. If it needs help from the server, those requests are made asynchronously, using XML. From simple to complex, Ajax applications can be of any size. It is an important development that has been made in the world of web applications and its importance is growing every day.
There are many Ajax web development companies, lending their valuable services in integrating Ajax. It has been used by many big companies in the world of the web. Many products of Google like Gmail, Orkut and sophisticated Google maps are based on Ajax technology. Likewise, the Yahoo maps are also dependent on this technology.