At what age is someone considered a child?

Generally, individuals under the age of 18 are considered children. Children can be further divided into several stages: those under 1 year old are classified as infants; ages 1–3 are the toddler stage; ages 3–7 are the preschool stage; ages 7 until the onset of puberty are the school-age period; and approximately ages 10 to 18 constitute adolescence. During childhood, it is important to enrich children's scientific knowledge, foster imagination, and develop personal interests and hobbies, ensuring their well-rounded development.