There are a lot of different versions of what Hypnosis is and none of them really clear things up. Hypnosis is a form relaxed concentration where the body and mind are in a peaceful and comfortable state.
Being ‘in hypnosis’ is a skill that you can learn and improve on, some people are more experienced than others but we all have the capability to learn how to enter a hypnotic state.
Notice, I don’t say ‘be hypnotised’ because it really doesn’t work that way. Hypnotists can’t force a person into hypnosis (and there’s been a ton of research in this area by the military) and it’s always down to the client to choose to go in to a hypnotic state.