Web-Service Specifications and Functions
Figure 3 shows a high-level grouping of the Web-service specifications published by IBM, Microsoft, and others. Note that this figure is not meant to imply a strict layering between the groups; instead, it is intended to provide an intuition about the relationships between functional areas. For example, Security does not require Description and, similarly, Description is a useful development-time concept for Messaging.
Figure 3. The interoperable Web services protocol architecture