[RyanN]

I've also heard of this, but cannot define it for you exactly as there is no real definition for it.

I believe it just means they have a shaft driving the wheels directly from the transmission instead of running wheels from a chain and sprocket without any real physical connection to the wheel. There are obvious advantages, as a live axle wheel has little to no chance of losing power. If all your chains fall off, the robot will likely still have mobility. It also can reduce weight since you eliminate chain and sprockets.