Web Services are an interoperable, platform independent mechanism for component interactions. SOAP decouples message representation from transport.
A Service Interface is described with WSDL and XSD files. A Service Implementation is disguised — Consumer is unaware of implementation details of the service
The Web Services Description Language (WSDL) is a standard for describing SOAP Service interfaces. Details of the WSDL design are covered later in the course. The formal WSDL specification is available on the w3 website: https://www.w3.org/TR/wsdl.html
The XML Schema Definition Language (XSD) is a standard for describing structures and validating XML documents. Details of the XSD design are covered later in the course. The formal XSD specification is available on the w3 website: https://www.w3.org/TR/xmlschema11-1/
Programs may use different transport protocols to send data across the network. You may design your software to implement message formats in a way that is not linked to any specific transport protocol. In this case you would be free to select alternative transports, yet continue to use same message structure. You would also be able to flexibly pass messages from one service to another without having to transform messages.