How WSDL describe a web service

Question

How does WSDL describe a web service? Illustrate your answer with the WSDL contract given in the lecture.

Answer 1

As communications protocols and message formats are standardized in the web community, this becomes increasingly possible and vital to be able to explain the communications in some structured manner. WSDL addresses this requirement by defining an XML grammar for explaining network services as collections of communication endpoints capable of exchanging the messages.

A WSDL document states services as collections of network endpoints, or ports. In WSDL, the abstract definition of messages and endpoints is separated from their concrete data format bindings or network deployment. This permits the reuse of abstract definitions: messages, that are abstract descriptions of the data being exchanged, and port types that are abstract collections of operations. The concrete protocol and data format specifications for a particular port type constitute a reusable binding. The port is defined by associating a network address with a reusable binding, and the collection of ports defines a service.