WCF vs Web Services
Both Web services and WCF enables you to fulfill you Service Oriented Architecture implementation. If Web Services can be used to make your architecture Service Oriented then why did Microsoft come up with something new called WCF. Sure WCF needs to have something over Web Services. Let’s see what WCF has in addition to what Web Services had. Here are some points:
1. Web Services and send messages only over HTTP, but WCF can, not only send via HTTP, but also TCP and other protocols
2. Web Services use Soap, WCF can use soap and also other formats like Representation State Transfer (REST) and simple XML
3. Web Services can only be hosted on Webserver; WCF can not only be hosted on Web Servers but has many other hosting options like Managed Applications, Managed Windows Services, Windows Process Activation Service (WAS). You can read more on WCF Hosting Options here: WCF Hosting Services
4. WCF has built-in support for reliable sessions and transactions. For Web Services its an add-on.
5. WCF also has built-in support for logging messages, tracing and managing configurations.