An object diagram is similar to a class diagram. It is used to give examples of values for all the attributes or showing how an object changes as the system runs and is divided into two compartments. The top compartment holds the name of the object, followed by a colon and the name of the class. Both the name of the object and the name of the class are underlined. The bottom compartment holds the names of the object's attributes and their values.

A diagram in the UML that shows the attribute values of specific objects and the relationships between objects. An object diagram is part of the static model of a system.