Hypnosis is a form of relaxed concentration where the Unconscious (Control Hub) part of the mind is given suggestions that it can decide to act upon.
Hypnotists usually call in the Unconscious but it is really totally conscious and aware of what is going on.
It is the part of the mind that makes all of the decisions, controls the body, executes habitual behaviour and operates all of the autonomous functions of the body.
Historically the mind was split into the Conscious and Unconscious/Subconscious.
The Conscious mind was considered the active part that made all of the decisions and was in control but recent advances in medical research has shown that the Conscious mind is little more than an interface between the real world and the 'Unconscious '.
It is the part of the mind that deals with interaction with other people and interpreting the internal decision making of the 'Unconscious' and explaining the why and wherefore of our behaviours.
I prefer the term Interface Hub.