Overview

Web services are modular, self-contained applications or application logic developed per a set of open standards. That much is immutable and indubitable. There is even concurrence of this application-centric viewpoint from the World Wide Web Consortium (W3C) (http://www.w3.org), the ultimate ratifiers of Web-related interoperability standards and in effect the godparents of Web services. W3C now has a definition, albeit in draft form, of Web services, within the emerging Web Services Architecture specification, which states categorically that a Web service is indeed a software system. This stake in the ground from W3C goes a long way toward helping rationalize prior conflicting views on exactly what constitutes a Web service, though it is only fair to note that this decisive description was formulated 2 years after the advent of Web services.

A Web service, however, is typically not meant to be a full-blown, feature-rich application in its own right even though, there are no restrictions as to how long, big, or complex a Web service can or should be. First, a Web service does not necessarily have to possess a user interface. This alone runs counter to most people s concept of what constitutes an application. Consequently, a Web service, though it needs to be characterized as an application for technical integrity, is better thought of as a mini-application, possibly even an application segment, or better still as an application enabler.

Some...