The Use Case Model comprises a set of Use Case Diagrams. Use cases model how a system is going to be used in a given context, giving you an overall picture of the system from a user's point of view.
You can view the Use Case Model part of a model through the Use Case Model folder in the Relationships pane.
The following sections provide information about the item and diagram types that are used in the Use Case Model. For more information about a diagram or item, click it.