What are the two common types of brakes used in vehicles?

Drum and disc brakes are the two most prevalent types of braking systems in vehicles today. Drum brakes consist of a hollow drum that rotates with the wheel, and shoes inside the drum that press outward against the inner surface to create friction and slow down the vehicle. This design is often used in the rear brakes of many cars, especially in older models. On the other hand, disc brakes have a flat, circular disc that is attached to the wheel. When the brake pedal is pressed, calipers squeeze brake pads against the disc, generating friction. This type of braking system is favored for its efficiency and cooling capabilities, and it is typically found in the front brakes of most modern vehicles.

The answer captures the widely recognized configurations of braking systems that drive vehicle engineering and design. While other types, such as hydraulic or wedge brakes, do exist, they do not hold the same prevalence in common vehicular applications as drum and disc brakes do. Hence, drum and disc brakes are the most appropriate choices when discussing common brake types.