Defining association roles (ends)
A role enables indication of one of the entities concerned by the association. Indication of roles is particularly important in the case of an association between an entity and itself.Each end of an association specifies the role played by the entity in the association.
The role name is distinguished from the association name in the drawing by its position at the link end. In addition, the role name appears in a normal font, while the association name is italicized.
The status bar (located at the bottom of the window) also allows identification of the different zones: when you move your mouse along the association, it indicates if you are on an association or on a role.When two entities are linked by only one association, the names of the entities are often sufficient to describe the role. Role names are useful when several associations link the same two entities.