Age refers to the length of time that someone or something has existed or has been alive. It is a measure of the chronological period since birth or creation. Age can apply to various aspects, including human beings, animals, objects, and concepts. Additionally, age can be relative, as it can be used to compare the maturity or development of individuals or groups. Age can influence societal roles and responsibilities, as well as physical and mental changes. It is often used to categorize individuals into different stages of life such as childhood, adolescence, adulthood, and old age.