The factor that largely determines the density of an object is its mass relative to its volume. Density is defined as the mass of an object divided by its volume and is typically expressed in grams per cubic centimeter (g/cm³). Different materials possess unique densities, influencing their buoyancy and behavior in various environments. For example, a denser object will sink in a less dense fluid, while a less dense object will float. Understanding density is crucial in fields such as engineering, physics, and materials science.