Object diagrams model the instances of things contained in class diagrams. An object diagram shows a set of objects and their relationships at a point in time.
You use object diagrams to model the static design view or static process view of a system. This involves modeling a snapshot of the system at a moment in time and rendering a set of objects, their state, and their relationships.
Object diagrams are not only important for visualizing, specifying, and documenting structural models, but also for constructing the static aspects of systems through forward and reverse engineering.
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