The Application Behavior viewpoint describes an Application Function carried out by an application detailing the internal behavior of an application; e.g. how it realizes one or more application services. This viewpoint is useful in designing the main behavior of applications.

An Application Collaboration is defined as a (temporary) configuration of two or more components that co-operate to jointly perform application interactions

An Application Service is defined as the externally visible (“logical”) functionality, which is meaningful to the environment and is realized by business behavior (Business Process, Business Function, or Business Interaction)

An Application Interface declares how a component can connect with its environment.

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 Function is defined as a representation of a coherent group of internal behavior of an application component.

An Data object is defined as a coherent, self-contained piece of information suitable for automated processing.