Describe how WSDL enables one to separate the description of the abstract functionality offered by a service from concrete details of a service description such as "how" and "where" that functionality is
Understanding WSDL - DZone Integration
Desarrollo de servicios web
Contract First SOAP Web Service - Roy Tutorials
Desarrollo de servicios web
Creating a WSDL Document For Type SOAP (Using the Database Binding Component)
How to Convert RPC/encoded WSDL into a Document/literal Wrapped WSDL