An AWD vehicle (short for All-wheel drive vehicle) is one with a powertrain capable of providing power to all its wheels, whether full-time or on-demand.

Four-wheel drive, 4×4 ("four by four"), 4WD, and AWD is a form of  drivetrain capable of providing power to all wheel ends of a two-axled vehicle simultaneously. It may be full-time (AWD), or on-demand (4WD/4×4), and may be linked via a transfer case to provide multiple gear ranges.