What is specific gravity?

Specific gravity is a measure of the density of a substance compared to the density of a reference substance, typically water. It is a dimensionless quantity and is often used to determine the concentration of a solute in a solution or to compare the density of different materials. The specific gravity of water is 1, so a substance with a specific gravity greater than 1 is denser than water, while a substance with a specific gravity less than 1 is less dense than water.