B형 (Blood) is one of the four main blood types in the ABO blood group system, which also includes A형, AB형, and O형. It is characterized by the presence of B antigens on the surface of red blood cells. People with B형 blood can receive blood from B형 and O형 donors, making it important for blood transfusions. Individuals with B형 blood can be further classified into B형 Rh+ or B형 Rh-, depending on the presence of the Rh factor. This classification is crucial for compatibility in blood transfusions and organ transplants. Understanding blood types, including B형, is essential in medical settings to ensure safe procedures.