When Richard Bandler was making studies of the leading therapists of the time, people such as Virginia Satire, Milton Erickson and Fritz Perls he discovered that the patterns of behaviour they demonstrated in their work had certain similarities even though they had very different personalities, therapeutic theories and styles. The patterns that they shared can be described in terms of hypnosis. This state is one that allows excellent communication with another part of the brain - the unconscious mind and this is what is often described as hypnosis.
People often think that they have never been in a trance.
As mentioned earlier, trance is all about the focus of a person's attention. The difference is that hypnosis is a deliberately induced trance where the hypnotist alters the subject's awareness through language and psychological techniques. While in hypnotic trance the conventional limitations and beliefs that determine everyday life are relaxed and new ideas may be considered by a person that result in new patterns of behaviour. That NLP and hypnosis share is that they work with patterns of behaviour. Richard discovered that hypnosis is a naturally occurring part of everyday life - we use is to influence states in others, to imagine what's going on inside someone's head, to replay experiences in our minds and in so many other ways.