HTTP handlers and HTTP Modules

Built-In HTTPHandlers:

HttpHandler	Purpose
PageHandlerFactory	Processes .aspx pages.
WebServiceHandlerFactory	Processes .asmx XML Web services.
HttpForbiddenHandler	Yields an error message indicating that a type of page is not in service. By default all .asax, .vb, .cs, .ascx, .config, .csproj, .vbproj, .webinfo files are mapped to this in machine.config.
StaticFileHandler	Delivers any page that isn't specifically mapped, such as .html, .htm, and .jpg.
TraceHandler	Shows the page containing all of the trace output.