Blood type A is one of the four main blood types in the ABO blood group system. Individuals with blood type A have A antigens on the surface of their red blood cells and produce anti-B antibodies in their plasma. This means they can receive blood from type A and type O donors but should not receive type B or AB blood. Blood type A is relatively common, with about 26% of the global population having this type. It is important for blood transfusions and organ transplants, as compatibility between donor and recipient blood types is crucial for preventing adverse reactions.