A ghost is considered to be the spirit of a dead person. Scientists say that there are no real ghosts, but many people believe that there are.
There are many stories about ghosts in books and movies. Sometimes the ghost is the spirit of a person who was killed by enemies or who died in a scary way. The ghost may stay on Earth because he or she is angry due to some problem in life and wants to scare people or to harm his or her enemies. Sometimes ghosts are said to live in a particular locality, for example an abandoned house, and when occupants come they tease them to drive away or cause serious damage to the occupants.
Sometimes the ghosts in these stories exist because of some problem the person had during life, that was not solved before he or she died. The ghost stays on the Earth trying to fix the problem. If the problem is fixed, the ghost can leave the Earth. Many ghosts stay on Earth also because they have died younger or have had sudden or abrupt deaths. Many people claim to have seen or heard ghosts. People who try to talk to ghosts as their job are called Mediums.
Many people believe they have seen ghosts. Others believe they have felt ghosts near them. Often the ghost is said to appear as a feeling of cold and a light or a misty cloud, but sometimes people say they have seen ghosts that look more like people. Sometimes ghosts are said to come in human form, that is, in the body of a person. Some ghosts might cause fear in the person who sees them, by being seen suddenly. Some ghosts are said to be friendly and help people who are in problems. The ghost might also appear as they did at the time of their death, including any blood or injuries. Ghosts can also appear and disappear as they wish. Many ghosts haunt the place they have died or a living loved one. Some may seek revenge or stay simply because they are confused.
Ghosts can form right after they die, or even centuries later. Many people make up stories or urban legends. many try to prove the existence of these paranormal creatures with special technology such as heat sensors. They also make TV shows dedicated to proving the existence of ghosts, often investigating cases where a person has seen one or visiting a place of sighting.