It's an extensible and flexible message-passing system. Basic
system: HTTP POST carrying an XML-encoded procedure call.
Trivialized, it's web forms being filled out by computers.
Components:
- SOAP, the RPC mechanism itself
- WSDL, an XML schema to help automate SOAP usage
- UDDI, a web service for locating web services
- WS{FL,EL,CM,XL,UI,...}, description/meta-data components (in
progress)
- ... probably lots of others ...