Difference between density and relative density?

Difference between density and relative density?

The ratio between density of a substance and density of water is called relative density.

  1. The ratio between density of a substance and density of water is called relative density.

  2. Relative density =

    Density of the substance/density of water at 40C
    
  3. Units: Relative density has no units because it is the ratio between the similar physical quantities (density).