What are Web services?
Christopher Ferris, Joel Farrell · Communications of the ACM · 2003
A Web service, as defined by the W3C Web Services Architecture Working Group, is "a software application identified by a URI, whose interfaces and bindings are capable of being defined, described, and discovered as XML artifacts. A Web service supports direct interactions with other software agents using XML-based messages exchanged via Internet-based protocols." 1 Others refine this definition further by requiring the description be a Web Services Description Language (WSDL) document and the protocol be SOAP.