A gearbox is a mechanical device that transmits power from an engine to the wheels of a vehicle. It adjusts the speed and torque of the engine's output, allowing the vehicle to move efficiently at different speeds. Gearboxes can be found in various types of vehicles, including cars, trucks, and motorcycles. There are different types of gearboxes, such as manual and automatic. A manual gearbox requires the driver to change gears using a clutch and gear stick, while an automatic gearbox shifts gears automatically based on speed and engine load. Both types play a crucial role in vehicle performance and fuel efficiency.