The terminology and standards relevant to Web services are:
- HTTP (Hypertext Transfer Protocol)
- HTTP is an application-level protocol for distributed, collaborative, hypermedia information systems. Its use for retrieving interlinked resources led to the establishment of the World Wide Web.
- XML (Extensible Markup Language)
- XML is a general-purpose specification for creating custom markup languages. It is classified as an extensible language, because it allows the user to define the markup elements. The purpose of XML is to aid information systems in sharing structured data, especially over the Internet.
- SOAP (Simple Object Access Protocol)
- SOAP is a protocol specification for exchanging structured information
in the implementation of Web services in computer networks. It relies
on XML as its message format. For an overview of SOAP, see Figure 1.Figure 1. Overview of SOAP
- UDDI (Universal Description, Discovery and Integration)
- UDDI is a platform-independent, XML-based registry for businesses
worldwide to list themselves on the Internet. UDDI is an open industry
initiative, sponsored by the Organization for the Advancement of Structured
Information Standards. For an overview of UDDI, see Figure 2.Figure 2. Overview of UDDI
Figure 3 shows the UDDI registry data exchange between the publisher of the service and the user of the service published in the UDDI.
Figure 3. Data exchange between the publisher and the user
- WSDL (Web Services Description Language)
- WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint.
- JAX-RPC (Java API for XML-based RPC)
- JAX-RPC is an application program interface that enables Java developers to include remote procedure calls (RPCs) with Web services or other Web-based applications.
