UML Distilled: A Brief Guide to the Standard Object Modeling Language, Second Edition

Object Diagram

An object diagram is a snapshot of the objects in a system at a point in time. Since it shows instances rather than classes, an object diagram is often called an instance diagram.

You can use an instance diagram to show an example configuration of objects. (See Figure 6-1, which shows a set of classes, and Figure 6-2, which shows an associated set of objects.) This is very useful when the possible connections between objects are complicated.

Figure 6-1. Class Diagram of Party Composition Structure

Figure 6-2. Object Diagram Showing Example Instances of Party

You can tell that the elements in Figure 6-2 are instances because ...