Web services are Web-based enterprise applications that use open,
XML-based standards and transport protocols to exchange data with client applications.
Web services allow the use of a language- and environment-neutral programming
model.
Web services use the following core technologies:
- XML (Extensible
Markup Language). XML solves the problem of data independence. You use it
to describe data, and also to map that data into and out of any application
or programming language
- WSDL (Web
Services Description Language). You use this XML-based language to create
a description of an underlying application. It is this description that turns
an application into a Web service, by acting as the interface between the
underlying application and other Web-enabled applications.
- SOAP (Simple Object Access Protocol). SOAP is the
core communications protocol for the Web, and most Web services use this protocol
to talk to each other.