1. Windows Communication Foundation (WCF) is an SDK for developing and deploying services on Windows. 2. WCF provides a runtime environment for your services, enabling you to expose CLR types as services, and to consume other services as CLR types. 3. Although in theory you could build services without WCF, in practice building services is significantly easier with WCF. 4. WCF is Microsoft’s implementation of a set of industry standards defining service interactions, type conversion, marshaling, and various protocols’ management. 5. Because of that, WCF provides interoperability between services. 6. WCF provides developers with the essential off-the-shelf plumbing required by almost any application, and as such, it greatly increases productivity. 7. The first release of WCF provides many useful facilities for developing services, such as hosting, service instance management, asynchronous calls, reliability, transaction management, disconnected queued calls, and security.