roughly speaking there are 3 classes of people who sit behind the wheel
steerers, generally do no maintenance or prestarts, know nothing about the vehicle and dont care, the kind of trucky who can get the truck from yard to yard but wont load it, unload it or do more than the barest minimum to make his pay dont care about the vehicle, tend to abuse the vehicle and dont report anything wrong untill its broken down and a minor fault has become a major repair
operators, do their own basic maintenance and prechecks, will report faults, go point to point, park the truck in a good position for load unload and help out with the lash/unlash. dont really care about the vehicle but dont try to abuse it but if it happens it happens
drivers do some preventative maintenance, do some of the more involved maintenance and repairs, are intimately familiar with the vehicles capabilities and requirements, know how to best integrate with the load/unload team, don't abuse the vehicle and usually have enough situation awareness to prevent getting into the situation where the vehicle gets abused.
of course some people prefer to put it down as steerer, driver, operator.
one of the highest compliments I've been paid as a landy driver was from a cruiser driver who cut short a cheque book wheeler mid torrent with simple line of "careful mate, it may be leaf sprung, underpowered and outdated but thats a stock landy and so far hes had less trouble than you"

