Newborns can be divided into term, preterm and term infants. Term infants are born at a gestational age of 37-42 weeks; preterm infants are born at a gestational age of less than 37 weeks, of which those born at a gestational age of less than 28 weeks are extremely premature or super immature; term infants are born at a gestational age of more than 42 weeks. According to the birth weight of newborns, they can be classified as normal birth weight newborns, low birth weight babies, very low birth weight babies, ultra-low birth weight babies and huge babies. The neonatal period has its own special physiological characteristics, such as neonatal jaundice, weak resistance and sensitive skin mucous membranes, so attention should be paid to reasonable care to smoothly pass the neonatal period.