From http://www.w3schools.com (Copyright Refsnes Data)

Introduction to WSDL

WSDL is an XML-based language for describing Web services and how to access them.

What You Should Already Know

Before you continue you should have a basic understanding of the following:

XML
XML Namespaces
XML Schema

If you want to study these subjects first, find the tutorials on our Home page.

What is WSDL?

WSDL stands for Web Services Description Language
WSDL is written in XML
WSDL is an XML document
WSDL is used to describe Web services
WSDL is also used to locate Web services
WSDL is a W3C recommendation

WSDL Describes Web Services

WSDL stands for Web Services Description Language.

WSDL is a document written in XML. The document describes a Web service. It specifies the location of the service and the operations (or methods) the service exposes.

WSDL is a W3C Recommendation

WSDL became a W3C Recommendation 26. June 2007.

You can read more about the XML Schema standard in our W3C tutorial.