This document outlines the different stages of human development from birth through old age, including infancy from birth to 1 year old, childhood from 2 to 12 years old, adolescence from 13 to 19 years old, adulthood from 20 to 59 years old, and old age from 60 years old and above. It notes that as humans progress through these stages, they grow taller and bigger and their appearance changes.