Brake pads are the link between the brake's calipers/pistons/arms and the rim/disc. When a force is aplied throught the braking system through either a cable or hydraulic means, the pads are forced to contact the rim/ disc. this causes frction against the braking surface and slows the brake down.

On magura rim brakes the commom pad material is commonly rubber or plastic ( monothane ). With disc brakes the pad is made of an organic compound.