Helper- Staff's first line of defense. Not technically staff, but can rank you up to forester. Also has direct access to important information about the server; feel free to ask!
Helper+- Helper's older brother. They can rank you up all the way to Sky Pilot! Also, they can fly. So there's that too.
Moderator- The power of the sun... almost in my fingertips. As a general rule, don't ask staff to WorldEdit things. Partially because not all moderators can in the first place.
Mod+- Can in fact WorldEdit things. Still don't ask.
Admin- Has sunglasses.
Owner- Take a guess.