Q:

Asp. NET Handler and Generic Handler

In Visual Studio 2010, when you say new Item, you can see Asp. NET Handler and Generic Handler.  Can you tell me what's the difference, I  think it came with .NET 4.0 because I couldn't find related thins on Google. 
Thanks. 

A:

I think your confusion probably comes from Visual Studio's use of terminology. 
An "ASP.NET Handler" is actually a HTTP handler which is "the process that runs in response to a request that is made to an ASP.NET Web application.  The most common handler is an ASP.NET page handler that processes .aspx files.  When users request an .aspx file, the request is processed by the page handler." 
A "Generic Handler" (.ashx) is a type of HTTP handler.  Generic handlers are the "default HTTP handler for all Web handlers that do not have a UI and that include the @ WebHandler directive." 