[A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] object An object is an instance of a class, or an instance of several classes in a generalization-specializ object creation 2nd 3rd asynchronous synchronous object deletion 2nd 3rd asynchronous synchronous object lifeline 2nd object reference An object reference is a value that refers to an object. object reference set An object reference set holds a set of object references. object:action action:object |