Activity (UML)

An activity is a major task captured by a Unified_Modeling_Language software design that must take place in order to fulfill an operation contract. Therefore, an activity can represent the invocation of an operation, a step in a business process, or an entire business process. Activities can be decomposed into subactivities, until at the bottom where we find atomic Actions. Consequently, from the semantic point of view, an Activity is a specialization of an Action as defined in UML (in other words, the base class of the Activity stereotype is the class Action).