Sleep duration refers to the amount of time an individual spends sleeping during a specific period, typically measured in hours.
Rapid Eye Movement (REM) Sleep: A stage of sleep characterized by rapid eye movements and vivid dreaming.
Non-Rapid Eye Movement (NREM) Sleep: A stage of sleep that includes deeper, more restorative sleep without rapid eye movements.
Sleep Deprivation: The condition of not getting enough sleep, which can lead to various negative effects on physical and mental health.