What is the relationship between WCF and REST&SOAP? Is WCF based on one of those technologies (REST or SOAP) or it is a separate technology?
WCF isn't automatically REST or SOAP, but you can make it that way. What you need here is a tutorial:
WCF
http://www.codeproject.com/Articles/406096/A-beginners-tutorial-for-understanding-Windows
REST
http://rest.elkstein.org/
Here's some other interesting stuff:
WCF - REST / SOAP
https://msdn.microsoft.com/en-us/library/hh323708(v=vs.100).aspx
WCF and REST
https://msdn.microsoft.com/en-us/library/ee391967.aspx
Or you can do a google/bing/metacrawler/altavista search on your own.....