Here's the definitoln of "Ghost" in Encyclopedia Horrifica.
Ghost: When the mind survives the death of the body.
"The big 3":
Poltergeist: The spirit of a living person under depression or stress. Yes, a person and that person's poltergeist can be in the same place and both be active.
Haunting: When an enviornment "Records" intense events or emotions. For example, you may hear crying in a hotel room where a murder took place, like a scary DVD stuck on repeat.
Apparition: These are your standard "Ghosts" but however, you do not (by definition) see them. They project an image of themselves into your mind, explaining how they become "Invisible" and pass through walls. They can look like anything.
