Brake shoes and brake pads are components of different types of braking systems. While brake pads are a component of disc brakes, brake shoes are a part of drum brakes.
Before getting into pads and shoes, it is important to know the difference between the two types of brakes. Disc brakes will usually be visible through your rims, as shown in this image.
Drum brakes will not be so easily visible but the absence of a disc will tell you they're drum brakes.
Brake pads are components of disc brakes. They squeeze the disc to slow down the vehicle.
Brake shoes fit inside drum brakes. When the brake is pressed, the shoes spread and press on the drum, slowing the car down.
While disc and drum brakes can be used as rear brakes, drum brakes are not used as front brakes. Brake pads cannot be used with drum brakes, nor can brake shoes work with discs.
