WCF Stand for windows communication foundation.
WCF is a single package solution for Web Service, COM+, Remoting, MSMQ.
Lets consider below requirement and find the solution from the software development and architecture point of view.
I will be opening a new company and need a software to communicate and deal with the existing software application of different company. existing one company has a software in web service, another has a software in COM+, another one has in MSMQ, and another one company has design its software in Java. Now the requirement is that my newly created software must be able to communicate with all the existing techonology in single handed application. so how to design such application. The answer is WCF.
WCF consist of WCF Client and WCF Service.
Through WCF service we can directly communicate with Web service which is design on HTTP or IIS server. Web Service only support for HTTP Platform.
We can also communicate with .Net application design for remoting using nettcp protocal.
We can also maintain transaction in WCF to Replace COM+ using system.transaction reference.
We can also send the messages in WCF to replace MSMQ.
WCF service can also maintain state and session.