Density is all about the compactness in molecular arrangement in any substance which decides how heavier or lighter any substance is.
Density is a characteristic property of a substance. The density of a substance is the relationship between the mass of the substance and how much space it takes up (volume). Density equals the mass of the substance divided by its volume; D = m/v. Objects with the same volume but different mass have different densities. Density is defined as mass per unit volume.
Let us Consider ice cubes on the water we could see ice floats on water which tells us that water is denser than ice.
Density is calculated using the below formula. It is represented by $\rho$.