According to the third edition of the article, “Scientist explore the chemistry of dreams”, written by the author Harold Schmeck, there are two types of sleep, in which dreams vary in performance. The first type of sleep is known as REM (rapid eye movement) sleep, and the second type of sleep is known as non-REM. Both types of sleep differ mainly from the level of consciousness. During a non-REM sleep dreams are vague, not easily remembered and the person who sleeps is not affected by his dream. On the contrary, in REM sleep dreams are highly vivid, the person who sleeps is aware that he is dreaming and might take control of the situation and modify it his