In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive. Sometimes "powertrain" is used to refer to simply the engine and transmission, including the other components only if they are integral to the transmission.
A motor vehicle's driveline consists of the parts of the powertrain excluding the engine and transmission. It is the portion of a vehicle, after the transmission, that changes depending on whether a vehicle is front-wheel, rear-wheel, or four-wheel drive,