Spirit

A spirit is a soul that was formerly a human that passed away. Depending on what kind of life the spirit led while they were alive and how they died, their destination in death may be to a peaceful place (in the case of Elise, who remarked that she had indeed come from a heavenly place to help Josh and Carl defeat Parker and Michelle Crane) or to a dark dimension known as the Further or to somewhere far worse.

The tortured ghosts that are lost inside the Further are seemingly damned to endure a miserable existence forever, unless an astral projector travels in the Further by mistake, which allows a spirit to gain another chance at life. However, this takes time and spiritual energy to do this and may cause the physical body to decay if successful.

Demons
A demon is a dark, satanic being that is usually portrayed as malevolent, sinister, evil, wicked, and sadistic. So far, there is only one known demon that lives in the Further: The Lipstick Demon, sometimes called the Red-faced Demon or simply the Demon. While the Long-Haired Fiend is sometimes called the Long-Haired Demon, it is unknown whether he is actually a spirit or lesser demon, although it seems likely he is the former.

Known Spirits
Such spirits might include:
 * The Long-haired Fiend
 * Doll Girl
 * Bride in Black
 * The Dancing Boy
 * Demon
 * Crying Woman
 * Parker's Mother
 * Dark-haired Woman