Services
Services are units of functionality that are accessible over a network through interfaces defined in a standardized way. The underlying transport used to invoke services is not fixed and a whole range of transports can be used as required such as synchronous HTTP or asynchronous messaging. A service is supplied by a service provider and is used by a service consumer. Mediation between services, for instance to allow a consumer to find a required service, is also part of SOA.
Currently services are typically provided over the Web using technologies associated with the Web and standards controlled by the World Wide Web Consortium (W3C). Services implemented in this way are called Web services. Web services are the preferred way to implement SOA at present. The technologies used for the implementation of Web Services are:
| Web Services Description Language (WSDL). WSDL is used to fully specify Web service interfaces using XML.
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| Simple Object Access Protocol (SOAP). SOAP is the protocol used when interacting with a Web service
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| Universal Description, Discovery, and Integration (UDDI). UDDI is a specification for the publishing and discovery of Web services. UDDI is XML based.
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