Before an external system can utilize a web service, it requires information on how to access and communicate with the service. Web Services Definition Language (WSDL) addresses this need by defining an XML grammar for describing network services as collections of communication endpoints capable of exchanging messages. WSDL allows Web Service interface descriptions to be stored as XML documents for distributed systems and serve as a recipe for automating the details involved in applications communication. Tools or systems can access the XML documents and subsequently understand how to access and utilize the service.

GBIF supports WSDL for web service interface descriptions, and IABIN will adopt it as a standard.