Simple Object Access Protocol (SOAP) is an XML-based protocol that lets you activate an application,
or even an individual object or method within an application, across the Internet.
SOAP was developed by Microsoft, DevelopMentor, and Userland Software and has been proposed
as a standard interface to the IETF(Internet Engineering Task Force).
SOAP is a way for a program running in one kind of
operating system to communicate with a progam in the
same or another kind of an operating system by using
the World Wide Web's Hypertext Transfer Protocol (HTTP)
and its Extensible Markup Language (XML) as the mechanisms for information exchange.
In SOAP there are several different types of messaging patterns,
but by far the most common is the Remote Procedure Call (RPC) pattern,
in which one network node (the client) sends a request message to another node (the server),
and the server immediately sends a response message to the client.
A major design goal for SOAP is simplicity and extensibility.