A Ghost, or Veiled Matter, was the soul of a deceased supernatural person that could, under certain circumstances, appear as a visible manifestation to the living from the Other Side. In even rarer circumstances, ghosts could physically interact with the living world. However, following the destruction of the Other Side in Home, the term is defunct.
Souls of supernatural beings can continue to linger for an indeterminate amount of time as spirits in the Space In-between until they find peace or move on to another afterlife.
Ghosts do not appear any different dead than they did when they were alive. Whenever they appear to the living, they are usually seen dressed in the very same attire they were wearing at the time of their deaths. However, it's possible that ghosts can somehow change their appearance and manifest different clothing; Bonnie Bennett, Vicki Donovan and Lexi Branson were shown wearing different clothing on the Other Side than the outfits they originally died in.
Powers and Abilities
Intangibility: Ghosts cannot physically feel nor can they be physically felt, unless they are given a physical foothold in the land of the living.
Species-Specific Abilities: Should a supernatural being become a ghost, they will still possess their given supernatural abilities. In addition, witches can still perform feats of magic while on the Other Side to directly affect the living world.
Isolation: Ghosts can only interact with the living through mediums and witches. However, if the person chooses to isolate themselves from the ghost, they will be forced to vanish. With the exception of witches, ghosts are even isolated from one another and for all intent and purposes, alone.
Witchcraft: Ghosts are susceptible to the forces of witchcraft. Since the Other Side was destroyed by a spell, all the ghosts who couldn't come back to life either got sucked into the dark void or found peace.
The Other Side was the mysterious dimension where the souls of dead supernatural beings reside. It was created by Qetsiyah in an attempt to imprison the immortal Silas. The spell ensured that every supernatural being that died would go to the Other Side, instead of the peaceful afterlife. While ghosts on the Other Side could, during moments where the Veil was down, manifest themselves and were able to interact with the living world, either to cause harm or to help.
Qetsiyah was indirectly responsible for the existence of ghosts by creating the Other Side, preventing the souls of deceased supernatural beings from finding peace and trapping them in a sort of limbo.
The ghosts of deceased witches known as The Spirits and are the only types of ghosts that are not bound to solitary and can interact with one another and retain their ability to influence the physical world through their magic. They are a collective force and known to carry out consequences on behalf of Nature before the collapse of the Other Side.