Web Service Definition Language (WSDL) Documents

Web services are described in documents expressed in WSDL. When interacting with a web service, a process will adopt one of two roles - supplier or consumer.

A service provider publishes a WSDL document that describes the services it offers.

A service consumer uses the published WSDL document to determine the services offered by the supplier and the messages required to access those services.

Abstract and Concrete WSDL Documents

WSDL documents are described as either abstract or concrete:

  • An abstract WSDL document describes what the web service does, but not how it does it or how to contact it. An abstract WSDL document defines:
    • the operations provided by the web service.
    • the input, output and fault messages used by each operation to communicate with the web service, and their format.
  • A concrete WSDL document adds the information about how the web service communicates and where you can reach it. A concrete WSDL document contains the abstract WSDL definitions, and also defines:
    • the communication protocols and data encodings used by the web service.
    • the port address that must be used to contact the web service.