The initial state is the state of an object before any events in the diagram have acted upon it.
A state represents an instant in the life of an object. Double-click a State shape to add a name and list its internal actions and activities.
TransitionsTransitions indicate that, in response to an event, an object will go from one state to another and perform an action.
The event which triggers the transition is named in the transition string. Double-click a transition to label it with a string that, in addition to an event signature, can also include a guard condition, an action expression, and more.