Web services (sometimes called application services) are
services (usually including some combination of programming and data, but
possibly including human resources as well) that are made available from
a business's Web server for Web users or other Web-connected programs. Providers
of Web services are generally known as application service providers. Web
services range from such major services as storage management and customer
relationship management (CRM) down to much more limited services such as
the furnishing of a stock quote and the checking of bids for an auction
item. The accelerating creation and availability of these services is a
major Web trend.
Users can access some Web services through a peer-to-peer arrangement rather
than by going to a central server. Some services can communicate with other
services and this exchange of procedures and data is generally enabled by
a class of software known as middleware. Services previously possible only
with the older standardized service known as Electronic Data Interchange
(EDI) increasingly are likely to become Web services. Besides the standardization
and wide availability to users and businesses of the Internet itself, Web
services are also increasingly enabled by the use of the Extensible Markup
Language (XML) as a means of standardizing data formats and exchanging data.
XML is the foundation for the Web Services Description Language (WSDL).
