The physical property that describes both volume and mass is density.

Here's why:

* Volume: The amount of space an object occupies.

* Mass: The amount of matter an object contains.

Density is a measure of how much mass is contained within a given volume. It is calculated by dividing the mass of an object by its volume:

Density = Mass / Volume

Therefore, density directly relates volume and mass, telling us how tightly packed the matter is within a given space.