A distributed application built with Web services is a service-oriented application. ASP.NET Web Services (ASMX) has been available for building Web services since .NET was first released. Why then do you need Windows Communication Foundation? WCF provides a number of benefits over ASP.NET Web Services, including:
- Support for sending messages using not only HTTP, but also TCP other network protocols.
- The ability to switch message protocols with minimal effort.
- Support for hosting services on hosts other than a Web server.
- Built-in support for the latest Web services standards (SOAP 1.2 and WS-*) and the ability to easily support new ones.
- Support for security, transactions and reliability.
- Support for sending messages using formats other than SOAP, such as Representational State Transfer (REST).