01) Interoperability
One of its key features is interoperability, that is, a single platform used to exchange information using various network protocols and platforms.
Typically, an Asp.Net web service uses https to communicate between client and server. Similarly, in .Net Remoting the client and the server must use .Net applications to share or exchange information. If one of your client (application) does not support .Net, it may not be able to accept or share information.
WCF services are interoperable, which uses a variety of network protocols such as https, TCP, MSMQ etc. Applications or services are designed for distributed environment using a single model.
02) Security and Reliability
WCF provides better security and reliablity as compared to web services or ASMX services. Security is a key element in any Service Oriented Architecture (SOA), and it is provided in the form of auditing, authentication, authorization, confidentiality and integrity of messages shared between the client and the service.
The service (or a program) is provided by WCF and it must ensure a reliable and secure architecture for exchanging data.
Security in WCF is a big subject and it requires a comprehensive understanding of the entire security process. Therefore, we have decided to cover it seperately.
03) Support for Plain XML, Ajax and REST
During the initial stages, messages sent across the network used a format called SOAP or Simple Object Access protocol. SOAP is a communication protocol used to exchange data (XML format) between applications. SOAP defines a common XML format used (by client and service) for requesting and replying messages.
WCF libraries now support other formats for sharing or exchanging messages (data) across the network. We can now configure WCF to share plain XML messages between clients and services, formats that are no more controlled by SOAP anymore.
There are other non XML formats such as Ajax and JSON, which are widely used for sharing messages using services provided by WCF.
We can now build WCF services using REST, also know by the name Representational State Transfer. It is simply an architecture to design distributed applications on a network, where clients can make requests for services. WCF provides a platform for developers to integrate REST with ease.