The Web Services Description Language (WSDL, pronounced 'wiz-dəl' or spelled out, 'W-S-D-L') is an XML-based language that provides a model for describing the functions of Web services.
For example, a banking Web service may implement functions to:
- check an account,
- print a statement,
- and deposit and withdraw funds.
These functions are described in a WSDL file that any consumer can invoke to access the banking Web service.
A WSDL file is a public contract that specifies:
- what the Web service looks like, such as the list of supported operations,
- the signature and shape of each operation,
- the protocols and transports that can be used when invoking the operations,
- and the XML Schema data types that are used when transporting the data.