A brake caliper is an assembly, part of a disc brake system. The caliper mounts to the vehicle and frames the rotor, acting as a clamp. The rotor spins until the caliper actuates, using a piston (or multiple pistons) to press the brake pads against the rotor, slowing it down with friction.
Calipers usually last the life of a vehicle when they are properly maintained. If an owner consistently changes the brake fluid and pads, the calipers are rugged and designed for longevity.
Price ranges for calipers range from $50 to $100 for basic aftermarket models to $1,000 and more for high-performance OEM models.
Some manufacturers use wheel designs that reveal the calipers as a point of pride, and red calipers are fashionable accessories for performance vehicles and supercars. Brembo is currently the signature caliper and brake brand, and some car listings may tout Brembo brakes as a selling point.
See also: What Are Brake Pads?, What Are New Brakes?, What Are Brake Rotors?