What is Service Contrat ?

1) What is Service Contract?
     It is collective mechanism by which a service's capabilities and requirements are specified for its consumers.
    In WCF, these mechanisms take the form of .Net interface or Class types, operations with in that type, and the following three core attributes, which are used to another these types and operations

    The three attributes are like
    * Service Contract Attribute



    * Operation Contract Attribute
    * Message Parameter Attributes.

Example :
    [ServiceContract()]
   public interface ITaskmanagerService
   {
     [OperationContract()]
     int AddTask(String taskDescription, string assignTo)
    }