SOA may be built on Web services standards that have gained broad industry acceptance. These standards, referred to as web service specifications, also provide greater operation and some protection from lock in to proprietary vendor software. One can, however, implement SOA using any service based technology.
Service oriented architecture is often defined as services exposed using the Web Services Protocol . The base level of web services standards relevant to SOA includes the following:
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XML - a markup language for describing data in message payloads in a document format
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HTTP (or HTTPS) - request/response protocol between clients and servers used to transfer or convey information
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SOAP - a protocol for exchanging XML-based messages over a computer network, normally using HTTP
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Web Services Description Language (WSDL) - XML-based service description that describes the public interface, protocol bindings and message formats required to interact with a web service
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Universal Description, Discovery, and Integration (UDDI) - An XML-based registry to publish service descriptions (WSDL) and allow their discovery
The web service does not necessarily need to use any or all of these standards to be service oriented. For example, some service oriented systems have been implemented using Corba, Jini and REST.
SOA can support integration and consolidation activities within complex enterprise systems, but SOA does not specify or provide a methodology or framework for documenting capabilities or services.