A service integration bus is a group of one or more application servers or server clusters in a WebSphere® Application Server cell that cooperate to provide asynchronous messaging services. The application servers or server clusters on a bus are known as bus members. In the simplest case, a service integration bus consists of a single bus member, which is one application server.
The service integration bus messaging provider uses service integration functions and is part of the WebSphere Application Server runtime environment. To use the default messaging provider, your applications must connect to a service integration bus. You can assign JMS queues (for point-to-point messaging) or JMS topics (for publish/subscribe messaging) as destinations on the service integration bus.