Ghosts are different. Ghosts are the souls of people after death. There are many kinds of ghosts. According to the fate, life experience, virtue and evil deeds of previous lives, ghosts can possess people to do things. Ghosts themselves have no ability to act, but ghosts can spell, both good and bad. Good ghosts can help others, bad ghosts can kill people, and some ghosts possess people in order to do something. There is no difference between good and bad. But zombies are definitely bad, because they are formed by resentment and full of hatred for the world. Their life activities and physique (so-called bad or not, not long ago) need human blood to support them. Without human blood, they won't die, but they will be weak.
Of course, ghosts and zombies don't exist, it's just human legends and fantasies.