What exactly is a sport utility vehicle or "suv" anyway?

[hassen1]

In the simplest possible terms -- a Sport Utility Vehicle (SUV) is a passenger vehicle with a flexible seating configuration and a cabin that includes a cargo area, and lacks a dedicated trunk. Most SUVs are built on a light truck platform, and many are equipped with 4-wheel drive or all-wheel drive.
For our purposes, we'll also include Crossover vehicles, SUV-like creatures that are built on a car platform.

[hilliebillie]

wat's the difference between 4wheel drive and all wheels drive???

all wheels, ain't that 4 as well, so what's the real difference between these two???