Chronotype refers to an individual's preference for timing of their daily activities, particularly sleep and wake times. It is often described as a person's internal biological clock or circadian rhythm. There are different types of chronotypes, with some people being "morning types" (early risers and peak performers in the morning) and others being "evening types" (night owls who are more alert and active in the evening). Chronotype is influenced by genetic and environmental factors, and can impact aspects of health, mood, productivity, and cognitive performance. Researchers study chronotype to better understand individual differences in daily rhythms and to explore potential implications for personalized medicine, lifestyle recommendations, and work schedules.