MSDN Webcast: Windows Communication Foundation Top to Bottom (Part 02 of 15): Contracts (Level 200)
Clients communicate with services by exchanging messages that are serialized on the wire, and de-serialized into Common Language Runtime (CLR) types at each end. In the simplest scenario, client and service developers only work with objects, and all the serialization magic happens somewhere down below in the plumbing. Windows Communication Foundation (WCF) provides this plumbing. The Web Services Description Language (WSDL) describes the protocols required to reach the service, the clients use proxies to communicate with the service, and messages just happen. The presenter of this webcast provides practical guidance for designing service contracts, data contracts, and message contracts - showing one when and how to employ each.