AWD is an acronym for All-Wheel Drive. All-wheel drive vehicles drive all four wheel all the time. This differs from 4 wheel drive vehicles in that they are mostly driven in 2 wheel drive mode and switched to 4 wheel drive when needed. The main difference that allows this is that all-wheel drive vehicles have a center differential. This allows the front and rear tires to rotate at different speeds when cornering. A different speed is needed because while turning the front tires travel a longer distance than the rear tires.
