Ghosts, also known as apparitions, hauntings, poltergeists, or spirits, are believed to be the souls or spirits of deceased individuals or animals that can appear to the living. The first recorded ghost encounter dates back to the 1st century AD, documented by Roman author Pliny, who wrote about an old man's ghost haunting his Athenian house. Centuries later, in 856 AD, Germany saw its first poltergeist case, where a farmhouse family was tormented by physical disturbances and eerie noises.