Rh-negative blood refers to the lack of a particular antigen on the surface of the red blood cells. There are several synonyms for this blood type, including Rh-null, Rh-deficient, and Rh-incompatible. Individuals with Rh-negative blood can receive Rh-negative or Rh-positive blood in a transfusion, but those with Rh-positive blood cannot receive Rh-negative blood. This is because the presence of the Rh antigen can trigger an immune response in those lacking it, leading to destruction of the transfused blood cells. Rh-negative blood is relatively rare, with only around 15% of the population possessing this blood type.