ASP.NET AJAX enables you to perform significant portions of a Web application's page processing in the browser, without requiring a round trip to the server to update the page. The ASP.NET AJAX development technologies integrate ECMAScript (JavaScript) client script libraries with the ASP.NET 2.0 server-based development platform. ASP.NET AJAX builds on the AJAX strategy for building Web applications, which enables you to make calls to Web-based applications from client script.
The ASP.NET AJAX development strategy enables you to build a new breed of Web application that has a number of advantages over traditional Web applications. AJAX-style applications offers: