Most new cars have a disc brake system on both the front and rear of the car. When the driver steps on the brake, the brake calipers squeeze the brake pads against the disc on each wheel, stopping the wheel from turning.
Older cars often have disc brakes only on the front wheels, with drum brakes on the rear. The friction needed to stop the wheels comes from brake shoes instead of pads. The shoes have a rough material on one side and sit inside the drum. When the brake pedal is pressed, the brake shoes, with the rough material, are pressed against the drum and the wheel stops.