What is the definition of density?

Beginners

For beginners, density is how closely packed together the molecules or particles of a substance are. A substance with high density has many particles tightly packed together, while a substance with low density has fewer particles that are spread further apart.

Intermediate

Density refers to the degree of compactness of a substance. It is measure by the amount of mass per unit volume. In simpler terms, it is how much "stuff" is packed into a specific space or area. For example, lead has a higher density than feathers because the same volume of lead will weigh more than the same volume of feathers due to lead's greater mass.

Advanced

Density is defined as the degree of compactness of a substance, measured by the mass of an object per unit volume, or the number of particles per unit volume. In physics, it may also refer to the amount of matter in a given space or the degree of opacity of a medium. In sociology, density can refer to the number of people or objects within a specific area. In computer science, it can describe the level of information within a certain amount of data.