composition
A strong form of aggregation association with strong ownership of parts by the composite and coincident lifetime of parts with the composite. A part may belong to only one composite at a time. Parts with nonfixed multiplicity may be created after the composite itself. But once created, they live and die with it (that is, they share lifetimes). Such parts can also be explicitly removed before the death of the composite. Composition is recursive.
See also aggregation, association, composite object.
Semantics
There is a strong form of aggregation association called composition. A composite is an aggregate association with the additional constraints that an object may be part of only one composite at a time and that the composite object ...
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