A newborn is a baby born within 28 days of birth from the time the umbilical cord is tied. Newborns can be divided into full-term babies and preterm babies. Full-term babies are those born at a gestational age of 37-42 weeks, while those born at less than 37 weeks are preterm babies and those born at more than 42 weeks are overdue. According to their weight, newborns can be divided into normal birth weight, huge babies, low birth weight babies, very low birth weight babies, and ultra-low birth weight babies. Normal birth weight is defined as weight between 2500-4000g, low birth weight infants between 1500-2500g, very low birth weight infants less than 1000g, and huge infants greater than 4000g. The neonatal period has many characteristics, such as physiological jaundice that can occur during this period. The resistance of newborns is also weak, so we must pay attention to reasonable care to avoid the occurrence of neonatal-related diseases.