There are Step by Step processes to know how HTTP request works.
1. If want to be able to interact with the low level processes, such as how the web server processes incoming & outgoing HTTP Request.
2. Before coming of HTTP Modules and Handlers to work with Web server & to control IIS operation uses forced to create ISAPI Extreme or Filter. Which is not easy due to creating it user need to know about c/c++ knowledge in low level.
3. IIS is the basic end point for incoming HTTP Request its job is to listen for & validate incoming HTTP Request. Than it routes them to appropriate modules for processing & return any results to the original requestor.
