WCF is the latest technology from Microsoft for building services, including web services. In this section, we will explain what WCF is and what it is composed of. We will also explain various .NET runtimes, .NET Frameworks, Visual Studio versions, the relationships between them, and what is needed to develop or deploy WCF services. You will see some code snippets that will help you to further understand WCF concepts although they are not in a completed WCF project. Once we have grasped the basic concepts of WCF, we will develop a complete WCF service and create a client application to consume it, in the next chapter.