Abstraction   An abstraction is a type of dependency and therefore a directed relationship between one or more clients (tail end) and one or more suppliers (arrowhead end). The elements represent the same concept but may be an expression of the concept at different stages of evolution, be views that hide or reveal detail, or be a representation from a different viewpoint. An abstraction can be used as an element in its own right, although it has a number of stereotypes that make its application more precise.

Explanation

An abstraction is a type of dependency indicating that one or more model elements are simply an expression of the same concept that is represented by another set of model elements. It is most commonly used in its singular form, with one element at the tail end (client) of the relationship and one element at the arrowhead end (supplier). There are a number of standard stereotypes that give the abstraction more precise meaning. We see this concept in our daily lives; for example when we see a picture of something in a catalogue, we know this isn't the thing itself but an abstraction of the item.

Related Entries

Dependency  Base Type A dependency is related to an abstraction because it is the base element for the abstraction relationship. The abstraction specializes the more general dependency relationship, conveying a meaning of evolution, different viewpoint or perspective. There are a number of standard stereotypes that may be added to an abstraction that further qualify its meaning and these add more precision to the less specific or standard abstraction relationship.