WCF is Microsoft’s unified programming model for building service-oriented applications

What makes WCF so unique?

– Programming model

– Scalability

– Interoperability

– Enhanced communication

– Enterprise enabled

Programming Model

The great thing about WCF is that there is no “right way” to get from point A to point B. If fact, WCF lets users start at point A and go to point B any way they see fit. This is because the programming model in WCF lets developers control how and when they want to code things and yet gives them the ability to do that with a minimum amount of code.
There are only a small handful of major components that a developer will need to work with to build high-class services. However, WCF also lets developers drill down to lower-level components if they desire to get more granular with their options. WCF makes this very simple. The WCF programming model lets a developer take whichever approach he or she desires. There is no single “right” way.
The programming model also combines many of the earlier technologies, such as the ones mentioned earlier in the chapter (MSMQ, COM+, WSE, and so on), into a single model.

Scalability

WCF services scale, and they scale in all directions. Not just up or out, but in all directions. They scale out via routing mechanisms and farms. Services scale up by not being tied to a single OS or processor. Services scale up by the pure ability to deploy them on bigger and better servers and taking advantage of the new processor technologies that are starting to appear.
Services scale in by way of cross-process transports, meaning on-machine and cross-machine messaging and Object-RPC.
Services scale down by interfacing and communicating with devices such as printers, scanners, faxes, and so on.

Interoperability

How sweet is it to be able to build high-class services using a single programming model and at the same time take advantage of earlier technologies, irrespective of the OS, environment, or platform? WCF services operate independent of all of these.
WCF services also take advantage of the WS architecture utilizing the already established standards as far as communication and protocols are concerned.

Enhanced Communication

Services are not picky as far as transports, formats, or much else. You as a developer can choose from a handful of transports, different message formats, and surplus of message patterns. A service can use TCP, HTTP, Named Pipes, or any other protocol to communicate.
The reason it is this way is because, as you hopefully have figured out by now, communication is completely separate from the service. They are completely independent from one another.

Enterprise Enabled

A lot of times there is a give-and-take relationship when dealing with web services, interoperability, and other important features geared toward enterprises. As a developer you have to weigh performance versus security, or reliability. At what cost does adding transactional capabilities add to your solution? Up until now, having the best of all worlds was a mere pipe dream.
Well, now it is time to wake up and smell the technology because WCF provides the ability to have security and reliability without sacrificing performance. And you can throw transactions into the mix as well.
A lot of this comes from the standards of the web service architecture, allowing you to build enterprise- class applications.