This document provides a history and overview of blood transfusion and blood banking. It discusses key discoveries such as blood groups, advances that allowed longer storage of blood components, and current practices. Some key points include: Karl Landsteiner discovered the main blood groups in 1900 and was awarded the Nobel Prize; the first blood banks were established in the 1930s-1940s; advances now allow storage of red blood cells for 35-42 days; screening and testing helps reduce transmission of infections; and clinical guidelines recommend transfusions only when benefits outweigh risks for the patient.