A hypnosis induction is a method whereby the hypnotist or hypnotherapist prepares you to enter the hypnotic REM state.
As hypnosis occurs naturally, a good therapist will simply elicit the way you already experience it. They will ask you to talk about your own experiences of enjoyable hypnosis such as watching a movie, reading a book, relaxing on a beautiful beach, whatever.
The therapist will later use this to engage your memory and imagination with ‘hypnotic language’ that draws your attention into the imagined scene playing out in your mind’s eye.
Indeed, it takes just a minute or two of focused attention like this to access the REM state. It’s as if your brain hands over control to the right hemisphere for a period of inward attention, much like going into a dream at night.
There are other, more rapid hypnotic inductions. Indeed, Milton Erickson, probably the most famous hypnotherapist from the last century, would sometimes use a ‘handshake technique’ that could put his clients into a trance in seconds.
This technique relies, to a degree, on shock and surprise in an attempt to confuse or disorient the person’s conscious mind. With the conscious mind (and any resistance) bypassed, the subconscious takes over where powerful suggestions can be embedded quickly.