B- (Blood) is a type of blood group classified under the ABO blood group system. It is characterized by the presence of the B antigen on the surface of red blood cells and the absence of the Rh factor, making it Rh-negative. Individuals with B- blood can receive blood from B- and O- donors. People with B- blood make up a small percentage of the population, which can affect blood donation and transfusion availability. Blood type compatibility is crucial in medical situations, as receiving incompatible blood can lead to serious health complications. Understanding blood types helps ensure safe medical practices.