We initially described SOA without mentioning Web services, and vice versa. This is because they are orthogonal : service-orientation is an architectural（ ）, while Web services are an implementation（ ）. The two can be used together, and they frequently are, but they are not mutually dependent.
For example, although it is widely considered to be a distributed-computing solution, SOA can be applied to advantage in a single system, where services might be individual processes with well-defined（ ）that communicate using local channels, or in self-contained cluster, where they might communicate across a high-speed interconnect.
Similarly, while Web services are （ ）as the basis for a service-oriented environment, there is nothing in their definition that requires them to embody the SOA principles. While （ ）is often held up as a key characteristic of Web services, there is no technical reason that they should be stateless—that would be a design choice of the developer, which may be dictated by the architectural style of the environment in which the service is intended to participate.
