Apparition:

[Chronos]

The supernormal appearance of a dead person or animal, or of a living person too distant to be within the normal perception of the observer, apparitions are quite uncommon and are rarely seen more than once, apparitions of the dead which are seen repeatedly over a period of time and which apparently haunt the same location are commonly known as ghosts, most recorded cases or reports of apparitions are more likely to be associated with the living Doppelganger than of a dead person or animal, few sightings are visual, most however involve the sensing of a presence sometimes accompanied by touch, hearing strange noises, perhaps thumps, rapping's, moanings and smells of unexplainable odors.
 Some apparitions can seem quite normal and solid in appearance to the observer others see faint images, blobs, streaks or patches of light, including vortex's a new theory suggest that orbs seen by  the observer are now frequently reported as apparitions these are normally solid in shape of white appearance and will appear and disappear just as suddenly as an apparition, strange how these only seem to appear on photographs taken with digital cameras and rarely on 35mm film.