How Ghosts Work.
According to believers, a ghost is the spirit of a dead person that either has not moved on to the afterlife or has returned from it. The definition of “spirit” can vary. Some describe it as a person’s soul, while others believe it is an energetic imprint that a person leaves on the world.
Humans have believed in — or been skeptical about — ghosts for thousands of years. They’re even mentioned in the oldest known written work of literature, “The Epic of Gilgamesh.” Ghost stories are part of most cultures’ folklore, although the details vary considerably from region to region.