A few years ago, when Web services started out as a buzzword in the enterprise, the whole paradigm was associated with (and still is) associated with three concepts - SOAP, WSDL, and UDDI. Now, when enterprises are putting Web services into production, you will most likely see two out of the three stakes being driven into the ground, but I have yet to see any real adoption of the "dynamic" part of any Web services implementation. Web services are taking root as a very feasible platform for achieving service orientation (not the only platform, mind you), but none of the clients that I have interacted with have any plan to adopt a UDDI-based service registry in the near or long term.
W3C defines a Web service as "a software system identified by a URI, whose public interfaces and bindings are defined and described using XML. Its definition can be discovered by other software systems. These systems may then interact with the Web service in a manner prescribed in its definition using XML-based messages conveyed over Internet protocols."
