An infant (from the Latin word infans, meaning "unable to speak" or "speechless") is the very young offspring of a human. When applied to humans, the term is usually considered synonymous with baby or bairn (Scotland), but the latter is commonly applied to the young of any animal. When a human child learns to walk, the term toddler may be used instead.The term infant is typically applied to young children between the ages of 1 month and 12 months; however, definitions may vary between birth and 2 years of age. A newborn is an infant who is only hours, days, or up to a few weeks old. In medical contexts, newborn or neonate (from Latin, neonatus, newborn) refers to an infant in the first 28 days after birth; the term applies to premature infants, postmature infants, and full term infants. Before birth, the term fetus is used.
Upon entry into the air-breathing world, without the nutrition and oxygenation via the umbilical cord, the newborn must begin to adjust to life outside the uterus. Newborns can feel all different sensations, but respond most enthusiastically to soft stroking, cuddling and caressing. Gentle rocking back and forth often calms a crying infant, as do massages and warm baths. Newborns can be comforted by nursing, or may need to comfort themselves by sucking their thumb, or a pacifier. The need to suckle is instinctive and allows newborns to feed.
Newborn infants have unremarkable vision, being able to focus on objects only about 18 inches (45 cm) directly in front of their face. While this may not be much, it is all that is needed for the infant to look at the mother’s eyes or areola when breastfeeding. Depth perception does not develop until the infant is mobile. Generally, a newborn cries when wanting to feed. When a newborn is not sleeping, or feeding, or crying, he or she may spend a lot of time staring at various objects. Usually anything that is shiny, has sharp contrasting colors, or has complex patterns will catch an infant's eye. However, the newborn has a preference for looking at other human faces above all else
Care and feeding
Infants cry as a form of basic instinctive communication. A crying infant may be trying to express a variety of feelings including hunger, discomfort, overstimulation, boredom, wanting something, or loneliness.
Breastfeeding is the recommended method of feeding by all major infant health organizations. If breastfeeding is not possible or desired, bottle feeding is done with expressed breast-milk or with infant formula. Infants are born with a sucking reflex allowing them to extract the milk from the nipples of the breasts or the nipple of the baby bottle, as well as an instinctive behavior known as rooting with which they seek out the nipple. Sometimes a wet nurse is hired to feed the infant, although this is rare, especially in developed countries.
Adequate food consumption at an early age is vital for an infant’s development. From birth to four months, infants should consume breast milk or an unmodified milk substitute. As an infant’s diet matures, finger foods may be introduced as well as fruit, vegetables and small amounts of meat.
As infants grow, food supplements are added. Many parents choose commercial, ready-made baby foods to supplement breast milk or formula for the child, while others adapt their usual meals for the dietary needs of their child. Whole cow's milk can be used at one year, but lower-fat milk should not be provided until the child is 2 to 3 years old. Weaning is the process through which breast milk is eliminated from the infant's diet through the introduction of solid foods in exchange for milk. Until they are toilet-trained, infants in industrialized countries wear diapers. The transition from diapers to cloth undergarments is an important transition in the development of an infant/baby to that of a toddler. Children need more sleep than adults—up to 18 hours for newborn babies, with a declining rate as the child ages. Until babies learn to walk, they are carried in the arms, held in slings or baby carriers, or transported in baby carriages or strollers. Most industrialized countries have laws requiring child safety seats for babies in motor vehicles.