Sleep is essential for overall health, impacting various physiological and cognitive functions. During sleep, the body undergoes critical processes such as tissue repair, hormone regulation, and memory consolidation. Poor sleep or sleep disorders can lead to health issues like obesity, cardiovascular disease, and impaired immune function. **REM sleep** supports emotional regulation and cognitive functions, while **deep sleep** is crucial for physical restoration. Adequate and quality sleep improves mood, cognitive performance, and overall well-being. Understanding the science of sleep underscores its importance in maintaining health and highlights the need for effective sleep hygiene practices.