Hello Katie, i also get very confused with the terms used, i think the meanings get changed during translation
Clearance lights seem to be used on large trucks and trailers, to warn other drivers of the extremities of the vehicle, i can't see the term used in relation to cars, not in the UK at least
From what i understand the bulb nearest the clear panel in the bulb holder is the "clearance" lamp, what we in the UK would term the parking light, switched on when the light switch is turned anti-colockwise. This would also illuminate the boot/trunk
The other small bulb in front of this is the normal rear light, illuminates when the switch is turned clockwise, either position 1, driving lights (sidelights) or position2, dipped lights. This would also illuminate the boot/trunk
I think that's correct, i haven't actually ever bothered to check on my car
