WJ Prajumsook
Observer Pattern
The observer pattern is mainly used for implementing distributed event handling systems, in “event driven” software. In those systems, the subject is usually named a “stream of events” or “stream source of events”, while the observers are called “sinks of events”. The stream nomenclature alludes to a physical setup where the observers are physically separated and have no control over the emitted events from the subject/stream-source.
Source
Software design patterns in Java – Observer Pattern
