Web Services Study Guide
Introduction:
The Web in Web Services is, from the first point, a misuse: the term Internet Services would be more appropriate. The Web comes from the second point - the use of the HTTP and XML is already in use as a well-understood and well-debugged set of protocols which support the Web, and so it makes sense to reuse them in providing remote operations and those things connected with them. The third point is what makes web service requirements so different from a local RPC system. The fact that data is exchanged for business purposes and between different social entities means that accountability is required, rather than just reliable transmission. The common themes are:-
A departure from the web as a quasi-static information space to one in which interactions are the primary model
A use of HTTP, XML and other standards from the web architecture as the building blocks
A typical focus on enterprise wide and inter-enterprise operations
The vendors of software see web services as way to repackage existing capability in a way which makes it interoperable with other systems.
The security requirements for web services are dictated by the trust environments, whether it is intranet or b2b or b2c, etc
For b2b one needs not just reliability but accountability.

However, the essential part of Web services is the Interact relationship between a Service provider and Service requestor. This is the Web Service. Discovery agencies need not be used - they will