What is the different between the blood group "a rh 'd' positive" and "o rh 'd' positive"?

Group A and O: The different is one has blood group o+ - and the other has blood group a+. Group o has no antigen a and b, but has antibody to a and b. So, group o is a universal donor- and the blood can be given to people with different blood group. Group a has antigen a, and antibody b. So, can receive group a or o blood. Group o only can receive blood group o if needed any blood transfusion.