what is rem sleep

Rapid Eye Movement (REM) sleep is a unique phase of sleep in mammals and birds, including humans, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream vividly. It is also known as paradoxical sleep and is associated with physiological similarities to waking states, including rapid, low-voltage desynchronized brain waves. REM sleep typically occupies 20–25% of total sleep in adult humans, with the first REM episode occurring about 70 minutes after falling asleep. It is the stage of sleep where most dreams happen, and it is essential for memory consolidation, emotional processing, and brain development