What is WCF? Comparing it with MVC

Question

Hello,I am an trainee and I am assigned an task. Regarding that i have some queries.
I searched a lot for WCF and I just came up with a very breif overview. Can any one please explain me the comparision of WCF with  MVC architecture.
Actually I want to develop an system for company which will be deployed on the intranet using ASP.net
And I want to knw about the Silverlight also. Is it possible to have MVC architecture in ASP.net and Silverlight?