Every request into an ASP.NET application is handled by a specialized component called HTTP handler. It is the most important component for handling ASP.NET application requests.
It uses different handlers to serve different files. The handler for web page creates the page and control objects, runs your code and then renders the final HTML.
Following are the default HTTP handlers for ASP.NET :
Page Handler(.aspx) : Handles web pages
User Control Handler(.ascx) : It handles web user control pages
Web Service Handler(.asmx) : Handles web service pages
Trace Handler(trace.axd) : It handles trace functionality
