WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). WSDL is extensible to allow the description of endpoints and their messages regardless of what message formats or network protocols are used to communicate. The binding used, primarily, is WSDL in conjunction with SOAP 1.1, HTTP, and MIME. The 1EdTech standards that have services expressed using WSDL are Learning Information Services (LIS) and Resource List Interoperability (RLI).
