A bike brake is a mechanical device that slows down or stops a bicycle by applying friction to the wheels. There are two main types of bike brakes: rim brakes and disc brakes. Rim brakes work by pressing brake pads against the outer edge of the wheel, while disc brakes use a rotor attached to the wheel hub, providing more consistent stopping power in various conditions. Proper maintenance of bike brakes is essential for safety and performance. Regularly checking the brake pads for wear and ensuring the cables or hydraulic lines are in good condition can help prevent accidents. Riders should also adjust the brake alignment to ensure effective braking.