“Induction” just means an “entry point”. Dictionary.com defines it as: “the process or action of bringing about or giving rise to something”.
A hypnotic induction is just a technique to transition a subject into a hypnotic trance. There are hundreds of techniques.
Some inductions happen slowly, relying on relaxation to ease the subject into a trance. Others use the “startle reflex” to surprise the client into moving into a trance. Still, others use a monotonous action, like a pocket-watch swinging to bring about a trance.
The best induction is the one that works for you. Some people react better to one method than another and it’s my job to figure that out before we start.