Breast milk is especially important for sick children or premature infants. The breast milk contains important nutrients and immune substances that can protect the child against infections. It can also develop and mature the immune system and the central nervous system. Due to various reasons, some mothers are unable to offer their own breast milk to their children - these children can be dependent on donor milk for a shorter or longer period of time to get the help they need.

A human milk bank collects breast milk donations from mothers who produce more milk than their babies need. They pasteurize and appropriately store the donor milk in medical freezers, and provides it to infants born prematurely or with very low birth weight (or other reasons) in neonatal intensive care units upon request. You can look at a milk bank as an advanced kitchen, and it is often a part of the neonatal intensive care unit in hospitals. The milk banks recruits donors, do follow-ups, and deliver equipment to donors.