Viscosity and density are two different physical properties of matter. Viscosity is the resistance of a fluid to flow, while density is the mass of a substance per unit volume. There is no direct relationship between the two properties. A substance can be viscous and dense, viscous and light, or not viscous and dense. For example, honey is a viscous liquid that is denser than water, while alcohol is a less viscous liquid that is less dense than water.