What will happen in a client machine and in a server when I request a service from an url

Dear all,

          Can anybody tell me what will happen when I request for a service through an URL in .net.

I know that the request is processed by the IIS and send to the server from were we get the responce. But I want to know the internal processing taking place both in the client and in the server machine

Regards,
Sivaprasa C