Guided imagery used in a variety of therapeutic situations is facilitated by the Trance State. Even while daydreaming one goes immediately into a light trance. Sitting in front of a television one can go to trance easily, particularly children. Driving down the highway most people are in a trance. While reviewing memories of the past or pondering the future one slips into a trance.
Trance is a natural, normal state of mind.
It is not necessarily induced by artificial means as some dictionary might describe. It happens in the natural course of a day to everyone. What you do there is another. That is called the hypnotic effect. A hypnotic effect is when, while in a trance, the subconscious mind gets an idea and acts upon it.