What is the Rh blood type?
People with different blood types have proteins specific to that
blood type on the surfaces of their red blood cells (RBCs).
Rh factor "Rhesus factor" is type of antigens on the human blood
cell. The presence of this antigen in human blood given (+) besides
it's blood type. The absence of this antigen is given (-) besides
blood type. For example A- or A+.