Nutrition is the basic need of every living being, and it is especially important in infancy. The first year of a child's life is a period of intense growth and development where the child gets to know and adapt to the world. Furthermore, the infant needs adequate nutritional and energy support to ensure proper growth and development. In infancy, the basis of nutrition for the first 4 to 6 months is mother's milk as the "gold standard", which also has a nutritional and protective role. Breast milk provides an immune protective effect and has far-reaching psychological effects during breastfeeding on children and their mothers. Therefore, breastfeeding is not only a meal at the breast, but also a positive influence on the cognition, behavior and mental health of children and mothers. In cases where there are obstacles to breastfeeding, infant formula is provided, a so-called "formula" that mimics the nutritional composition of breast milk. As the child grows, usually up to the sixth month of life, milk is no longer sufficient to meet the infant's nutritional needs and it is necessary to start with supplementary feeding. Complementary food means any food that does not include milk. New foods are introduced according to the readiness and maturity of the digestive tract, that is, the psychophysical development of an individual child. The amount of meals and the spectrum of new foods increase with the age and energy needs of the child. The importance of adopting proper eating habits in the first year of life has a positive effect on the later age of the child. Undesirable reactions such as nutritional allergy or intolerance to certain foods in infants are not rare. Special caution is required when introducing foods that contain known allergens, as well as attention to their physical manifestations. The aim of this review is to emphasize the importance and describe the basic features and guidelines of infant nutrition