What is SOAP and how does it relate to XML?

SimpleObjectAccessProtocal is formatting protocol.

before transmitting data it converts in to xml formate.

Webservice works with combination of SOAP+HTTP.

SOAP-formatting protocal

HTTP-Transmisson protocol.

The Simple Object Access Protocol (SOAP) uses XML to define a protocol for the exchange of information in distributed computing environments. SOAP consists of three components: an envelope, a set of encoding rules, and a convention for representing remote procedure calls. Unless experience with SOAP is a direct requirement for the open position, knowing the specifics of the protocol, or how it can be used in conjunction with HTTP, is not as important as identifying it as a natural application of XML