A WSDL is an XML schema that describes the protocols, formats, and signatures of the web service operations.
A WSDL contains a description of the data to be passed to the web service so that both the sender and the receiver of the service request understand the data being exchanged. The elements of a WSDL contain a description of the operations to be performed on that data, so that the receiver of a message knows how to process it. The elements of a WSDL also contain a binding to a protocol or transport, so that the sender of a message knows how to send it.
You can view the WSDL of a web service in the Developer tool or in the Administrator tool. After you deploy a web service to a Data Integration Service, you can view the WSDL URL or you can download the WSDL to a file. When you access the WSDL URL that the Administrator tool displays, you can see the content of the WSDL.