disc brake [1]
Braking mechanism comprising a disc attached to the wheel, whose rotation is slowed down when the brake pads exert friction on it.
disc 
Round plate interlocked with the wheel whose rotation slows down as it is braked by the friction of the brake pads.
caliper 
Viselike part comprising a piston, which straddles the brake disc and supports the brake pads.
brake line 
Tube carrying the brake fluid, which becomes pressurized when the driver steps on the brake pedal.