Hypnosis can be described as an altered state of consciousness, just like daydreaming. Whilst in Hypnosis, changes can be made in the part of the mind that you don't consciously use, this is called the sub or unconscious mind.
Also while in Hypnosis you will feel relaxed and comfortable and will be able to hear Glenn's voice guide you to make the changes that you want to achieve.
Hypnosis is a perfectly natural state, and as such you will know exactly what is going on around you, while being completely relaxed.
Hypnotherapy is also about empowering the individual to make changes in their life.