Changes made to a region in the Model Explorer view are reflected in the diagrams owned by the same state machine and changes made to a region in the diagram editor are reflected in the Model Explorer view. You can set the canonical properties value of a region to false so that changes made to a region in the Model Explorer view are not reflected in the corresponding state machine diagrams and so that a region can be edited independently of other diagrams in the same state machine.
Parent topic: Modeling object behavior by using state machine diagrams
Related concepts
States, regions, and transitions