I’ve been researching this all day and cannot find the accurate differences between the two. Can someone please help? I need this information for a paper i’m writing.

Mario Kart Wii – how can I tell the difference between expert staff ghosts and the regular ghosts?
I mean on the time trials – when you beat the only ghost on the time trials with enough time to spare it unlocks an expert ghost. Those are what I’m referring to.

Ghosts may be the spirits of dead people while demons are just evil spirits, but they seem to have a lot in common. They are both spooky, hang out in the same spooky places, and have some overlapping attributes. Why does there seem to be a relation?