SOA(Service Oriented Architecture) is a technical term developed in 2000 and SOA is the concept of distributed programming.
Like Asp.Net and C#, for SOA also we write the program but some other program will call the SOA program.
Distributed Programming is the concept of writing a program in one system and allowing user to run in other system. That means you will have the program in one computer and several other computers will call this program is called Distributed Programming. In distributed programming two programs will communicate with each other.
Service is also a program and we develop the service for other programs. WCF(Windows Communication Foundation) is used to develop the services. Once you develop the service it should be available within the network or all over the internet depending on the restrictions.
Through WCF(Windows Communication Foundation) we can provide maximum security. Other than .Net, Java and Oracle also supports Distributed Programming.
In .Net we have three different options to develop distributed programming. Those are Remoting, Web Services and WCF.
In Remoting concept, server and client programs should be in .Net, that means it is not universal. Through Web service we cannot get the maximum security. By using WCF we can get maximum security and any client independent of platform can invoke WCF service.
WCF supports Native communication, Web Service Communication and also Cloud Computing. By using WCF we can get richest service development.
Service oriented means it should be component based and also Object Oriented. The hierarchy of Service Oriented is like Object Oriented ==> Component based ==> Service Oriented
Component based means indirectly it is object oriented only. Assembly is example of component based.
WCF Features
WCF has 18 communication agents and adding, removing agent is very each. For that you don't need any development techniques.
WCF supports Multiple Communication Options
Add/Remove Communication is completely isolated from Programming.
WCF is rich implementation of SOA.
WCF supports all protocols like HTTP/HTTPS, TCP/IP...etc