The biological clock refers to the internal mechanism that regulates various physiological processes and behaviors in living organisms, such as sleep-wake cycles, hormone production, and metabolism. These clocks are driven by molecular mechanisms involving genes and proteins that operate on a roughly 24-hour cycle, known as circadian rhythms. Research in this area focuses on understanding the molecular and cellular mechanisms of the biological clock, how it is synchronized with external cues like light, and its impact on health and disease. Studying the biological clock can provide insights into various aspects of human biology and potential treatments for circadian-related disorders such as sleep disorders, metabolic diseases, and mood disorders.