WSDL is a short form for Web Services Description Language, which is used to describe a Web service in terms of the messages that it creates and accepts. The WSDL document is an XML file that contains the interface schema for the Web service. It identifies the methods that are used during the exchange between a Web service consumer and a Web service provider. The following are the elements contained in the WSDL document:
Types - Describe the variations of data types that are used to exchange messages between the user and the provider.
Message - Describes the actual message or method call.
portType - Describes the set of operations and each related message.
binding - Describes the protocol details.
service - Used to make groups a set of related ports together.