4WD Versus IWD
The term Individual-wheel drive is coined to identify those electric vehicles whereby each wheel is driven by its own individual electric motor. This system essentially has inherent characteristics that would be generally attributed to Four-Wheel drive systems like the distribution of the available power to the wheels. The IWD drive is not limited to 4 wheels as there is generally a motor that drives each wheel that can number upwards of 4, but could also identify a single wheeled vehicle.
Read more about this topic: Four-wheel Drive