There are hundreds of Ajax frameworks out there. All of them abstract the little differences between browsers regarding XMLHTTP use. Web developer can use one of these frameworks (ASP.NET Ajax, jQuery, MooTools, Prototype, etc.). The ASP.NET Ajax framework is the one realized by Microsoft to easily enable Ajax in ASP.NET applications. ASP.NET Ajax is separated into two main sections:
-Server components – contain components to simplify development of Ajax behaviors using server-side code. The most important components in this section are the ScriptManager and UpdatePanel server controls.