What is DataContract and ServiceContract?

Data represented by creating DataContract which expose the
data which will be transefered /consumend from the serive
to its clients.

**Operations which is the functions provided by this
service.

To write an operation on WCF,you have to write it as an
interface,This interface contains the "Signature" of the
methods tagged by ServiceContract attribute,and all methods
signature will be impelemtned on this interface tagged with
OperationContract attribute.

and to implement these serivce contract you have to create
a class which implement the interface and the actual
implementation will be on that class.


Code Below show How to create a Service Contract:

[ServiceContract]
Public Interface IEmpOperations
{
[OperationContract]
Decimal Get EmpSal(int EmpId);

}

Class MyEmp: IEmpOperations
{
Decimal Get EmpSal()
{
// Implementation of this method.
}
}