An application component is defined as a modular, deployable, and replaceable part of a system that encapsulates its contents and exposes its functionality through a set of interfaces.
An application component is a self-contained unit of functionality. As such, it is independently deployable, re-usable, and replaceable. An application component performs one or more application functions. It encapsulates its contents: its functionality is only accessible through a set of application interfaces. Co-operating application components are connected via application collaborations.
An application component may be assigned to one or more application functions, business processes, or business functions. An application component has (is composed of) one or more application interfaces, which exposes its functionality. Application interfaces of other application components may be used by an application component. The name of an application component should preferably be a noun.