AB0 blood grouping system
According to the AB0 blood typing system there are four different kinds of blood types: A, B, AB or 0 (null).
Blood group A
If you belong to the blood group A, you have A antigens on the surface of your red blood cells and B antibodies in your blood plasma.
Blood group B
If you belong to the blood group B, you have B antigens on the surface of your red blood cells and A antibodies in your blood plasma.
Blood group AB
If you belong to the blood group AB, you have both A and B antigens on the surface of your red blood cells and no A or B antibodies at all in your blood plasma.
Blood group 0
If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma.