Web Services Description Language

From Wikipedia, the free encyclopedia

"WSDL" redirects here. For other uses, see WSDL (disambiguation).

The Web Services Description Language (WSDL, pronounced 'wiz-dull' or spelled out, 'W-S-D-L') is an XML format published for describing Web services. Version 1.1 has not been endorsed by the World Wide Web Consortium (W3C). Version 2.0, for which several drafts have been released, is expected to become a W3C recommendation.

WSDL is an XML-based service description on how to communicate using the web service; namely, the protocol bindings and message formats required to interact with the web services listed in its directory. The supported operations and messages are described abstractly, and then bound to a concrete network protocol and message format. This means that WSDL describes the public interface to the web service.

WSDL is often used in combination with SOAP and XML Schema to provide web services over the Internet. A client program connecting to a web service can read the WSDL to determine what functions are available on the server. Any special datatypes used are embedded in the WSDL file in the form of XML Schema. The client can then use SOAP to actually call one of the functions listed in the WSDL.

XLang is an extension of the WSDL such that "an XLANG service description is a WSDL service description with an extension element that describes the behavior of the service as a part of a business process" [1].

Resources or services are exposed using WSDL by both Web Services Interoperability (WS-I Basic Profile) and WSRF framework.