The basis of hypnosis is the direction of thought; either by the suggestions of a hypnotist or throught self-hypnosis. For example relax then, first think of a part of your body you can feel (perhaps a foot) then think of something outside your body (perhaps a car driving by or the light on a wall) then lastly think of something you will do tomorrow (perhaps log onto Answers). You have just directed your thought to something inside you and something outside you and something entirely imaginary at this moment.
Your mind (the “I” when you say I have a body) is like the conductor of a huge orchestra constantly directing everything you consciously see or here or think about. When you are unconscious say in non-REM sleep your conductor is taking five and you are not having thoughts, only static.