A Bone Marrow Donor is a person who voluntarily provides their bone marrow to help someone with a serious illness, such as leukemia or lymphoma. Bone marrow is a soft tissue found in the center of bones, responsible for producing blood cells. Donors can be matched with patients through a registry, and the donation process can involve either a surgical procedure or a non-surgical method called peripheral blood stem cell collection. The donation process is safe and typically involves a thorough medical evaluation to ensure the donor's health. After the donation, the recipient can receive the healthy stem cells, which can help restore their immune system and improve their chances of recovery. Organizations like the National Marrow Donor Program work to connect donors with patients in need.