What does the WSDL describe about a web service?

The Web Services Description Language (WSDL) provides a comprehensive description of the public interface of a web service, including the methods available and the data formats used. It serves as a contract between the service provider and the consumer, outlining how the service can be interacted with, what operations are available, and the structure of the requests and responses. This detailed information allows developers to understand how to communicate with the web service effectively, ensuring that both sides are aligned in terms of expectations and implementation.

For example, a WSDL file specifies the operation names, the message types that are used in their communication, and the protocols (such as SOAP) to invoke those operations. Through this structured description, developers can auto-generate client code and documentation, facilitating seamless integration of the web service into applications. Hence, the WSDL is essential for defining how systems can interact over a network by clearly stating the expected inputs and outputs, along with the format for message exchange.

The other options do not accurately capture the purpose of a WSDL. The WSDL does not describe the internal structure of the server or detail the programming language used, which are not relevant to the service's public interface and functionality. It also goes beyond just listing available methods, as it encompasses all aspects