[cire]

I am not 100% sure but from what ive seen and heard I think that crab is defined by just being able to drive in any direction, Swerve is like driving a car where not all of the wheels are pointing the same direction. So I would be able to push a button and it will just drive like a crab, and all 4 wheels will rotate together - meaning crab drive. Or i can push the other button and it will switch to where it will drive more like a car with only the front wheels rotating. I can also push the other button and it would drive like a tank.