According to MSDN, "Web Services are based on a core
set of standards that describe the syntax and semantics of software
communication: XML provides the common syntax for representing data; the Simple
Object Access Protocol (SOAP) provides the semantics for data exchange; and the
Web Services Description Language (WSDL) provides a mechanism to describe the
capabilities of a Web service." Web services are based on the SOAP
protocol for exchange of data in heterogeneous environments.