The measurement of how much mass contained in a given volume is called density. Density is defined as the mass of an object divided by its volume. It is typically expressed in units of kilograms per cubic meter (kg/m3) or grams per cubic centimeter (g/cm3). Density is an important property of matter as it can provide information about the composition, structure, and phase of a substance. For example, denser objects tend to be more compact and have a higher concentration of mass than less dense objects. Additionally, density can be used to determine the purity of a substance, as impurities can alter the overall density of the material.