This section is adapted from Geary and Horstmann, Core JavaServer Faces [Sun Microsystems Press 2004].
In recent years, web services have emerged as a popular technology for remote method calls. Technically, a web service has two components:
A server that can be accessed with the Simple Object Access Protocol (SOAP) transport protocol
A description of the service in the Web Service Description Language (WSDL) format
SOAP is an XML protocol that, like CORBA's IIOP, provides a protocol for invoking remote methods. Just as you can program CORBA clients and servers without knowing anything about IIOP, you don't really need to know any details about SOAP to call a web service.
WSDL is analogous to IDL. It describes the ...