B - Brakes
Brakes - There are two types of brakes: discs and drums. Few cars now use drums, and all modern cars have discs at the front. With drum brakes, a cylinder (the drum) is attached to the wheel hub and turns with it. Inside, pads are pushed against the drum to stop the car.
A disc brake is a steel disc fixed to the wheel hub, and the stopping force is applied by brake pads clamped in callipers that push in against the disc. Disc brakes are more efficient because they dissipate heat better for improved repeated performance, need much less adjustment and provide greater stopping power.