From the factory, trucks tend to sit with the front end lower than the rear end, usually by 2 or 3 inches or so.
When a truck is "leveled" that means that someone has replaced some of the suspension parts on the front only, and lifted just the front of the truck up by 2 or 3 inches so that it sits level.
When a truck is lifted, there are two ways to do it. Either a suspension lift or a body lift.
A suspension lift replaces suspension components in the front and rear, and lifts the entire truck up. The height of the lift is based off of how much the front is lifted, because suspension lifts usually also level the truck in addition to lifting it.
So a 6 inch lift would raise the front by 6 inches, while it wouldn't necessarily raise the rear by 6 inches.
A body lift uses blocks and raises the body off of the frame all the way around and doesn't level the truck, so the height of the lift is just the height of the blocks.
To me, it looked like your truck had been lifted and not just leveled, but it appears I've been outvoted.
Hopefully someone will come up with stock measurements so you can know for sure.