Internal combustion refers to a process where fuel is burned inside a chamber, producing energy. This energy is used to power engines, commonly found in vehicles like cars and motorcycles. The combustion occurs in a confined space, allowing for efficient energy conversion. The most common fuels used in internal combustion engines are gasoline and diesel. These engines operate by igniting the fuel-air mixture, which creates high-pressure gases that push against pistons. This movement ultimately turns the engine's crankshaft, generating mechanical power to drive the vehicle.