When you open a modeling diagram, it is displayed in the diagram editor. The model file, location in the model, and diagram name are displayed on the tab at the top of the diagram editor. You can have multiple diagrams open at the same time and use the tabs to navigate between the them.
Parent topic: Graphically representing models by using modeling diagrams
Parent topic: Creating use case diagrams
Related concepts
Types of modeling diagrams
Canonical behavior in modeling diagrams