Non-REM, or non-Rapid Eye Movement sleep, is a phase of sleep characterized by slower brain waves and a lack of eye movement. It is divided into three stages, ranging from light sleep to deep sleep. During this time, the body undergoes essential processes such as tissue repair, growth, and immune system strengthening. This sleep phase is crucial for overall health and well-being. It helps consolidate memories and supports cognitive functions. Non-REM sleep typically occurs in cycles throughout the night, alternating with REM sleep, which is associated with dreaming and increased brain activity.