The human life cycle can generally be broken down into 6 different stages. The first stage occurs in the womb, during fetal development. The second stage is the baby or infant stage, which spans from birth until 1 year of age. Next is childhood; this stage typically covers from 1 to 12 years of age.
Sometimes, this stage is broken into 3 sub-stages, which include toddlerhood (1-3 years), preschool (3-5 years), and primary school (5-12 years). The fourth stage is adolescence, which spans ages 13 to 19. This is followed by adulthood, spanning ages 36 to 65. Ages 65 and up constitute the final, sixth stage of human life. The life cycle ends at different times for each person, depending on when they die.