I have been thinking about this topic again today and I have come to a conclusion.
The definition of trance is: a half-conscious state characterized by an absence of response to external stimuli, typically as induced by hypnosis or entered by a medium.
Trance: Elves don’t need to sleep. Instead, they meditate deeply, remaining semiconscious, for 4 hours day. (The Common word for such meditation is “trance.”) While meditating, you can dream after a fashion; such dreams are actually mental exercises that have become reflexive through years of practice. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.
meditation definition: Meditation is the act of remaining in a silent and calm state for a period of time, as part of a religious training, or so that you are more able to deal with the problems of everyday life.
semiconscious: That part of the mind which is on the fringe of consciousness and contains material of which it is possible to become aware by redirecting attention.
sleep: a periodic state of physiological rest during which consciousness is suspended and metabolic rate is decreased .
The important part of this paragraph to point out is “meditate deeply” which basically says you’re not reading a book, sewing a dress or baking a pie.