The term "hypnosis" comes from the Greek word hypnos, meaning "sleep."
Hypnotherapists use exercises that bring about deep relaxation and an altered state of consciousness, also known as a trance. A person in a deeply focused state is unusually responsive to an idea or image, but this does not mean that a hypnotist can control the person's mind and free will. On the contrary, hypnosis can actually teach people how to master their own states of awareness. By doing so they can affect their own bodily functions and psychological responses.