The Web Services Description Language (WSDL) is an XML format published for describing Web services. Version V 1.1 has not been endorsed by the World Wide Web Consortium (W3C), however it is now working on a new version 2.0, that will be a recommendation (an official standard), and thus endorsed by the W3C.

It is commonly abbreviated as WSDL in technical literature and often pronounced "Whiz-Dull".

WSDL describes the public interface to the web service. This 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.

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.

See also

• Web Service
• SOAP
• WSIF
• UDDI
• WS-I Basic Profile
• List of Web service markup languages
• Comparison of Web service markup languages

External links

• WSDL 1.1 Specification
• Web Services Description Working Group
• XML protocol activity
• Online WSDL Validator
• Another Online WSDL Validator
• W3Schools WSDL tuturial