When some people hear the terms 4-wheel-drive and all-wheel-drive, they tend to think that the two terms are the same thing. In some ways that are true, but in fact, they are two separate applications of all four wheels on a vehicle having power instead of just two.
Four-wheel-drive has been around longer, so it is more familiar to most people. This type of powertrain uses a lower gear ratio and a split differential in order to power all four wheels. This is found mainly on pickup trucks and larger SUVs that are used in off-road situations.
