"아가 (Baby)" refers to a very young human, typically from birth to around two years old. During this stage, babies undergo rapid physical and cognitive development. They learn to recognize faces, respond to sounds, and begin to communicate through cooing and babbling. In many cultures, including Korean culture, babies are often seen as symbols of innocence and joy. Care for a baby usually involves feeding, changing diapers, and providing a safe environment for exploration. Parents and caregivers play a crucial role in nurturing a baby's growth and development during these formative years.