A software concept and infrastructure — supported by several major computing vendors (notably Microsoft and IBM) — for program-to-program communication and application component delivery. The Web services concept treats software as a set of services accessible over ubiquitous networks using Web-based standards and protocols.
Specifically, a Web service is a software component can be accessed by another application (such as a client, a server or another Web service) through the use of generally available, ubiquitous protocols and transports, such as Hypertext Transport Protocol (HTTP). Joint efforts between IBM and Microsoft, with the support of other vendors such as Ariba and Iona Technologies, have produced agreement on a basic set of XML-based standards for Web service interface definition, discovery and remote calling. They include:
• Web Services Description Language (WSDL) for describing Web service interfaces
• Universal Description, Discovery and Integration (UDDI) as the means for users to publish and locate available Web services, their characteristics and interfaces
• Simple Object Access Protocol (SOAP), which enables an application to call a Web service
See HTTP, .NET, SOAP, UDDI, WSDL and XML.