I have read that web services are transmitted through SOAP over HTTP. Then what is the difference between SOAP and HTTP, if they are both communication protocols?
Is there any difference or is HTTP simply a binding used by SOAP?
There are two main protocols related to web services.
1st, transport protocols - e.g. HTTP(commonly used), TCP, UDP
2nd, messaging protocols - e.g. SOAP, XML, JSON or binary encoded messages
Generally speaking,
A real world example: HTTP is like telephone communication, SOAP is like English.
You call the web service over HTTP in SOAP messages such as you call your friend by mobile phone and talking in English.