Other systems interact with the Web service in a manner prescribed by its description using SOAP messages, typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.] A Web service is an abstract notion that must be implemented by a concrete agent.
(See Figure 1-1) The agent is the concrete piece of software or hardware that sends and receives messages, while the service is the resource characterized by the abstract set of functionality that is provided.
This publication as a Working Group Note coincides with the end of the Working Group's charter period, and represents the culmination of the group's work.
Discussion of this document is invited on the public mailing list [email protected](public archives).
2 Concepts and Relationships provides the bulk of the conceptual model on which conformance constraints could be based.
For example, the resource concept states that resources have identifiers (in fact they have URIs).
The aim here is to demonstrate that Web services can be made secure and indicate which key concepts and features of the architecture achieve that goal.
The key stakeholder's perspectives supported in this document reflect the major goals of the architecture itself: interopability, extensibility, security, Web integration, implementation and manageability.
It identifies the functional components and defines the relationships among those components to effect the desired properties of the overall architecture.
While the concepts and relationships represent an enumeration of the architecture, the stakeholders' perspectives approaches from a different viewpoint: how the architecture meets the goals and requirements.
In this section we elucidate the more global properties of the architecture and demonstrate how the concepts actually achieve important objectives.
To illustrate this distinction, you might implement a particular Web service using one agent one day (perhaps written in one programming language), and a different agent the next day (perhaps written in a different programming language) with the same functionality.
Although the agent may have changed, the Web service remains the same..