Human milk oligosaccharides (HMOs) contain numerous biomolecules. It is the third most abundant solid component of breast milk, after lactose and lipids, that plays an important role in infant growth and the development of human life. Several studies have reported the health benefits of HMOs, which include modulation of the intestinal microbiota, antiadhesive effect against pathogens, modulation of the intestinal epithelial cell response, development of the immune system, increasing the intestinal barrier and so many health benefits can be achieved through the presence of HMOs in breast milk. Infant growth is indirectly or directly dependent on so many compounds of the biological and chemical composition of mother milk, HMOs are one of them. The genetic background of the mothers and the diversity of HMOs are determined and the nonsecretor mothers secrete lower HMOs than secretor mothers. The breastfed infants of secretor mothers gain more health benefits than those of non-secretor mothers. Here the study critically reviewed the role of HMOs in proper growth, immune system, and development in ensuring the health impact of infants and toddlers. The study also focuses on current knowledge of the HMOs study and the beneficial effect of HMOs types and their importance to infant growth and protection against NEC. HMOs are applied now in infant formulas to imitative nutrition composition of breast milk and their study and challenges are vastly discussed in a specific manner in the human study. In conclusion, it is stated that the supplementation of infant formula with 2′-FL and LNnT is a promising innovation for infant nutrition.