What is the Difference Between Similar But Different Things, Terms, and Objects

What is the Difference between Monsters, Aliens, Demons, Ghosts and Zombies

Monsters, Aliens, Demons, Ghosts and Zombies are the names of some supernatural or fictional characters that we commonly hear many times in our routine life. the proof of their existence is another chapter, but many people think that all these names are used for same fictional creature.