SOAP messages are transmitted between applications and may pass through a number of intermediaries as they travel from the initial sender to the ultimate recipient.
Commerce can only take place when there is a match between demand and offer. A
recurrent problem for businesses is how to reach their potential customers and
future partners with information about their products and services. UDDI
attempts to solve this problem on the Internet by providing an industry-wide
approach that allows companies to advertise both the business and technical
aspects of their offering.
The Web Services Description Language (WSDL) is an XML language for describing the syntax of Web Service interfaces and their locations. 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[Web Services Description Language (WSDL) 1.1].
XML stands for eXtensible Markup Language. XML was designed to facilitate the sharing of data across different systems, particularly systems connected via the Internet. XML is a "meta" language because it is used for defining markup languages. XML is a subset of the Standard Generalized Markup Language (SGML). A markup language defined using SGML or XML has a specific vocabulary (labels for elements and attributes) and a declared syntax (grammar defining the hierarchy and other features).