Spirits are those that have come from the grave to visit loved ones still on Earth while ghosts are people who have not yet "crossed over" after death. Some believe ghosts may still have unfinished business on Earth before they can cross over and be at rest.
Many people believe ghosts are more "hands-on" than spirits. They feel spirits come to watch over someone they were close to in life and offer protection, if possible. Ghosts may feel confused or frightened about the death experience, and therefore may be hesitant to leave.
Ghosts are often portrayed in a negative light while spirits are seen to be a positive, guiding force in the lives of those who encounter them.