Hypnotism is a trance state characterized by extreme suggestibility, relaxation and heightened imagination. It is not really like sleep, because the subject is alert the whole time. It is most often compared to daydreaming, or the feeling of "losing yourself" in a book or movie. You are fully conscious, but you tune out most of the things around you. You focus intently on the subject at hand, to the near exclusion of any other thought.

Milton Erickson, the premier hypnotism expert of the 20th century, contended that people hypnotize themselves on a daily basis. But most hypnotherapists focus on the trance state brought on by intentional relaxation and focusing exercises. This deep hypnosis is often compared to the relaxed mental state between wakefulness and sleep.