A brake is a mechanical device used to slow down or stop the motion of a vehicle. It works by creating friction against the wheels, which reduces their speed. Common types of brakes include disc brakes and drum brakes, each with its own design and function. Brakes are essential for safety in vehicles, allowing drivers to control their speed and stop when necessary. They are found in various modes of transportation, including cars, bicycles, and trains. Regular maintenance of brakes is important to ensure they function effectively and safely.