A nipple shield is a small, usually disposable, device that fits over the mother's nipple during breastfeeding. It can help to protect the nipple from damage or discomfort caused by the baby's teeth or strong sucking action while also allowing the baby to latch on and feed normally. Nipple shields are often used in cases where a mother is experiencing pain, cracked or bleeding nipples, or if the baby has difficulty latching on due to poor positioning or other issues. They can be helpful for both breastfeeding mothers and their babies, but should only be used temporarily while working on improving breastfeeding techniques and comfort.