Web services provide a standard communication mechanism to discuss two applications based on heterogeneous technologies. The communication relies mostly on the exchange of XML messages.Two architectures are commonly used. The first, service-oriented (SOA), based on a mechanism type PRC. The messages are conveyed via Soap or XML-RPC. Representational State Transfer (Rest) offers him a communication asynchronous based on existing technical infrastructure (HTTP and URL).Most standards and the oldest technologies were designed for an architecture based on Soap. While the new standards tend to take better account of the Rest architectures.Extremely many, the standard Web services are organized into layers that do not evolve at the same speed. Only foundations – Soap and WSDL – are now mature and stable. The security layer is organized around the proposal for a standard WS-Security, some elements of which mature. Transactions are the ground for a fierce fight between his clan, Sun, Oracle, Iona, Novell and IBM, Microsoft and BEA.
Two structures dominate the standardization of Web services. The W3C (World Wide Web Consortium) standards ratifies low-level (Soap, WSDL …), and Oasis (Organization for the Advancement of Structured Information Standards) federates initiatives highest level (security, transactions …) .