A blood bank is a facility that collects, tests, processes, and stores blood and its components for transfusions. These facilities ensure that donated blood is safe and available for patients in need, such as those undergoing surgery or suffering from medical conditions like anemia. Blood banks work closely with organizations like the American Red Cross to encourage voluntary blood donations. They maintain strict protocols to ensure the quality and safety of the blood supply, including screening donors and testing for infectious diseases before the blood is made available for use.