The handbrake (or parking brake) is used to keep your car from rolling when parked or during emergencies. It is separate from the main brake system.When to Use the HandbrakeWhen parking on slopes or hillsDuring traffic stops if waiting for a long timeAs emergency brake if the footbrake failsWhen starting on an incline, to prevent rolling backwardAlways disengage the handbrake before driving. Using it properly helps avoid accidents and protects your transmission and brakes.