XFS Introduction Looking back over the last six years, it is hard to imagine networked computing without the Web. From a client's point of view, if you can type, you can access services. The web services movement is about the fact that the advantages of the Web as a platform apply not only to information but to services . Microsoft's Passport , for instance, offers an authentication function exported on the Web. So hypothetically, an electronic newspaper like the Washington Post can avoid creating its own user authentication service, delegating it to Passport.
Web services are a new breed of Web application.
IBM's web services tutorial goes on to say that the notion of a web service would have been too inefficient to be interesting a few years ago. While middleware platforms provide great implementation vehicles for services, none of them is a clear winner. The strengths of the Web as an information distributor, namely simplicity of access and ubiquity, are important in resolving the fragmented middleware world where interoperability is hard to come by. The Web complements these platforms by providing a uniform and widely accessible interface and access glue over services that are more efficiently implemented in a traditional middleware platform. Viewed from an n-tier application architecture perspective, the web service is a veneer for programmatic access to a service which is then implemented by other kinds of middleware.