How does the State pattern differ from simply using an enum with a switch statement to control behavior?

The State pattern extracts each behavioral case into its own class implementing a shared interface, while an enum-and-switch keeps all cases as branches inside every method that needs to vary. The practical difference shows up when a new case is added: with State, you write one new class and touch nothing else; with an enum and switch, you have to find and correctly update every method that branches on that enum, and it is easy to update most of them and silently miss one. State also lets each case hold its own behavior — and even its own transition logic — in one place, whereas a switch scatters the logic for one case across however many methods branch on it. In short, State trades a small amount of extra class-file overhead for a much stronger guarantee that adding new behavior cannot accidentally break existing code paths.