The different stages of human life are fetus, infancy, childhood, adolescence, adulthood and old age. The human life cycle starts at fertilization, goes through the embryonic stage and the fetal stage. After fetal growth and birth, the second stage is infancy, which is the period between birth and one year.
During infancy, a child learns to walk, eats solid food, and has some teeth. Childhood follows after infancy and is a period that last from the first year of life to about the age of 10. Between the ages of 11 and 13, a child can enter the pubescent stage and adolescence begins. This stage occurs typically between the ages of 10 and 19.
In adulthood, humans have a completely developed body. In their 20s, humans are at their peak. From the age of 30 to old age, the aging process begins and some noticeable signs are thinning skin, the appearance of wrinkles and muscle mass decreases.