Hypnosis is an altered state of consciousness that often involves comfortable states of relaxation. It also allows your mind to be in a heightened state of awareness. We all go in and out of trance at various times of the day and night. Daydreaming is a good example of being in a trance as is driving on a motorway and not being consciously aware of how far you have driven.
In an FLP session you will be in a light state of trance and be aware of everything around you but feeling comfortably relaxed at the same time.