A service-oriented architecture emphasizes structuring of an application into largely independent services that are composed to form various applications. An example of a service-oriented architecture is illustrated on Figure 1.2, “Service-Oriented Architecture Example”.
Service-oriented middleware emphasizes support for service integration, which is carried out by independent integrators rather than by the service developers. Independent integration requires support for service deployment, service location, declarative rather than imperative service composition, and other features that lead to loosely coupled architectures.