WCF means Windows Communication Foundation. It is used for designing distributed applications under SOA implementation. At CATT Ltd we follow some of the specifications of WCF:
Distributed Applications may require reliable messaging for this purpose WCF implements WS-Reliable messaging. Applications which are built on WCF can communicate with other applications through WS-Basic Profile. It also provides secure information to the clients and send asynchronous messages from one server to another server.
Web API is a set of HTTP request messages that allows to pull data from client to server. It makes possible for disconnected systems to communicate through the use of REST Web Services. With the boom of APIs in the market, Internet has got power to merge multiple applications together. At CATT Ltd we worked on number of Web APIs for web as well as mobile applications for many projects.
Windows Services is an application like another it operates in background. They are intended to provide operating system features such as web serving, event logging, Printing and error reporting. One of the advantage using Windows Service is they can be started during the system boot, before the other programs and even before you login. Security suites is a very good example as they install different services to provide real-time monitoring of the system activities. At CATT Ltd we create Windows Services in Visual Studio.