Basically wcf abstracts the service (a .net interface) and the transport (or in wcf terms, a binding). A single service in Wcf can be exposed as a web service or using shared memory without any actual code changes, the endpoints are all based on app config files.
WCF = Windows Communication Foundation A communication-oriented set of APIs and a "runtime" inside .NET to make two (or more) systems talk to one another. It basically replaces ASMX (ASP.NET web services), .NET remoting (object remoting) and a few other communication-related API's and products in the .NET space. It can and should be used any time two systems (apps, machines) need to exchange ...
WCF is really just a networking / communication platform. What you do with it is up to your requirements and skill. Typically it is used in situations where you have a client -> server or n-tier application. Most commonly it is hosted by IIS or Process Hosting service on a server. Then connected to by some client. WCF does have the ability to transfer data, including images as a byte stream ...
.net - What is WCF? and what can it do? - Stack Overflow
I understand to an extent that it helps applications communicate regardless of their location. Why is it important and what is an example of a real-world use of WCF?
Why is WCF so important and in what cases is it used?
Windows Communication Foundation (WCF) Windows Communication Foundation (WCF) is Microsoft’s unified programming model for building service-oriented applications. It enables developers to build secure, reliable, transacted solutions that integrate across platforms and interoperate with existing investments.