Post: What are brake calipers, brake discs, and brake pads

Brake calipers, brake discs, and brake pads
Most modern vehicles are equipped with brake discs. This braking system connects the wheel to a metal disc that rotates with the tire and wheel hub.
The caliper works by slowing the wheel down by creating friction with the rotor. It is essentially a clamp that fits around the brake disc.
Because the material of the brake pad is softer than the metal of the brake disc, the brake pads tend to wear out faster. You will find that the brake pads need to be replaced more often than the brake discs, and it is easy to understand why once you understand how the brake system works.
Every time you press the brake pedal, the rotation of the brake disc causes the brake pads to wear a little thinner. Over time, the brake pads are eroded by the metal disc and begin to wear out.
The brake pads are the friction material that fits on both sides of the caliper. When you apply the brakes and press the pedal, the pressure stored by the brake fluid pushes the pistons toward the caliper. This causes the caliper to squeeze the brake pads against the brake disc, which slows down the spinning wheel by restricting its ability to move freely. When this process occurs on all four wheels simultaneously, it slows the car down in a controlled manner and eventually brings the vehicle to a complete stop.