Rh negative is a type of blood group. The common blood groups as we all know are blood group A, B, AB and O. To further classify each of these blood groups are either positive or negative for example A+, A-, B+, B- etc. A+ means blood group A Rh positive and A- means blood group A Rh negative and so forth. Rh positive and Rh negative depends on the presence or absence of a particular type of factor in our body called Rh factor.