Use Composition

Object diagrams demonstrating composition are similar to class diagrams showing composition. Most of the time, however, each separate object is given its own box, the actual values of the attributes are shown more often, and the relationship is generally not explicitly specified.

Depending on circumstances, different attributes of a class or object may or may not be shown in any one diagram. Much of the time, you are trying to show only certain attributes. In these cases, it's permissible to omit the attributes you aren't interested in. Simplifying a diagram by omitting the irrelevant parts of an object or class should make a diagram more intelligible.

Click the Quiz link below to take a short quiz on class and object composition.
Class Object Composition - Quiz