A Message Bus pattern describes the principle of using a system that can send and receive messages using one or more communication channel, so that applications can interact without knowing details about one another. This a design methodology where interaction between applications is accomplished by passing asynchronous messages over the bus. Common Message Bus leverage architecture either leverage a messaging router, or use a publish and subscribe pattern, and are implemented using a messaging system such as a queue. Many Message Bus implementations consist of individual applications communicating using predefined schema and a shared infrastructure for sending and receiving messages.