What makes a UML Composition different from an Aggregation or a regular Association?

The concepts of Association, Aggregation and Composition exist in UML since the first published versions, but the exact meaning of these concepts, especially the Aggregation still leads to heated debates among UML experts.

But before we go into the details, let’s have a look at how these concepts are defined in UML. I guess every UML user is familiar with the graphical notation, but how do these concepts look like in the UML (v 2.5) meta model?… Read more