Each person has a certain blood type of blood group. Each blood has two antibodies and two antigens. They are labeled A and B. When a blood does not have either antigen, then the blood is called O. The combinations can include antigen B with antibody A, antigen A with antibody B, without antigen with both antibody A and B and antigen AB but with no antibodies.
A genotype is the characteristics of the genetics of a person or animal or other living thing. It deals with the single traits and complex traits as well as groups of traits. If children have AO and BO genotype parents for the ABO blood group, then the children would have AO, BO, AB and OO only genotypes.