Age refers to the length of time from birth to calculation, usually expressed in years. Age is a natural sign with biological basis. After a person is born, with the passage of the sun and the moon, his age increases, which is an irresistible natural law.
People are breeding their own times at the same time, and the times are always composed of individuals of different ages born in different times. In addition, various demographic phenomena, such as marriage, childbearing, schooling, employment, migration and death, are closely related to everyone's age. Therefore, it is of great significance to calculate the age correctly.
Calendar age
That is, full age or full age-the age calculated according to the calendar after birth, also known as full age, is the most commonly used method to calculate age, which is simple and easy to master, and is also an objective record that is independent of human will.
Biological age
(Life span) namely physiological age: this is the age calculated according to the normal physiological and anatomical development state of human body, which indicates the actual aging degree of individual tissue structure and physiological function, and can be used to predict the future health status of individuals and estimate their life span. If a person is 60 years old, his biological age may be 60, 50 or 70.