Brake discs, also known as rotors, are essential components of a vehicle's braking system. They are typically made of cast iron or carbon composite and are mounted on the wheel hub. When the driver presses the brake pedal, the brake pads clamp down on the brake discs, creating friction that slows down or stops the vehicle. Brake discs come in various designs, including vented and slotted types, which help dissipate heat and improve performance. Regular maintenance, such as checking for wear and replacing worn-out discs, is crucial for ensuring safe and effective braking.