A perspective from which a view is seen.
UML incorporates a number of viewpoints, including real-world modeling, application analysis, high-level design, implementation modeling, and visual programming of existing languages. (The last is an unfortunate use of UML by many users who do not appreciate the power of abstraction and modeling.) The multiple viewpoints sometimes cause confusion because the same concepts may be used in different ways to accomplish different purposes. It is unfortunate that UML itself does not contain good ways to declare the viewpoint that a model expresses, but modelers should take care to separate different viewpoints into different models and to label each model with the viewpoint that it expresses. ...