What do we call children of different ages?

👶Newborn (baby): 0–3 months.

👶Infant: this term kind of means the same thing as baby, while ‘infant’ is a more formal term. It's something you would read on a medical text or research paper, but it means the same thing as baby.

🧒🏼Baby: this term is used to refer to a little one from birth up until the baby can walk.

👦Toddler: a baby turns into a toddler when they can ‘toddle', i.e. walk shakily. This usually happens around 1 year, but may occur earlier or later, depending on development.

🧒🏼Child: this is the oldest of all the terms in the question.

👦Legally, in many countries a child is anyone under the age of 18.

However, in common usage most people distinguish between a baby, child, preteen, and teenager.

👧🏼Ages 11–12 are preteens or adolescents.

🧑Ages 13–19 are teenagers.