Is type O blood the universal recipient or the universal donor or both?

Type O blood is the universal donor.

O blood group individuals do not have either A or B antigens on the surface of their RBC 's. Their blood serum contains IgM anti - A and anti - B antibodies. Therefore a group O individual can receive blood only from a group O individual , but can donate blood to individuals of any ABO blood groups. O negative blood group is compatible with anyone.