An Object Diagram shows a complete or partial view of the structure of a modeled system at a specific time. This snapshot focuses on some particular set of Class, Data Type, Interface or Signal instances and attributes. A correlated set of object diagrams provides insight into how an arbitrary view of a system is expected to evolve over time. Object Diagrams are more concrete than class diagrams, and are often used to provide examples, or act as test cases for the Class Diagrams. You can have many Object Diagrams in a model.
You can create an Object Diagram through the context menu of the Model or a Package: right-click the Model or a Package, point to New, point to UML, point to Structure, and then click Object Diagram.
The following sections provide information about how an Object Diagram is used in the model. For more information about an item, property or model part, click it.
For most diagram symbols, you can change the presentation of the symbol through the Style view options (See
Style view options - all diagrams), and change the showing of Stereotypes and Tag Definitions through the Stereotypes view options (See
Stereotypes view options for a symbol - all diagrams). When a symbol has additional view options for changing its presentation, this icon is shown - to see how the view options can change the presentation, click the icon.
is shown - to see how the view options can change the presentation, click the 
Comment
Constraint
Dependency
Instance
IO Flow
Slot (on Instances)
Model
Package
Instance Model
Stereotype