Gearboxes refer to the mechanical component that transmits power from the engine to the vehicle's wheels. In the automotive industry, the term gearbox is widely used interchangeably with other terms such as transmission or gearset. However, there are several other synonyms for gearboxes that are less commonly used, including drivetrain, gear case, speed changer, and powertrain. Drivetrain refers to the combination of all components responsible for transmitting power from the engine to the wheels, including the gearbox. Gear case specifically refers to the enclosure that houses the gearbox. Speed changer highlights the gearbox's primary function of changing the vehicle's speed. Lastly, powertrain is a broader term that encompasses all components responsible for generating power and transmitting it to the wheels, including the gearbox.