The principle that describes the dispersal of particles in a fluid is known as diffusion. Diffusion occurs when molecules move from an area of higher concentration to an area of lower concentration, seeking equilibrium. This process is driven by the kinetic energy of particles and is fundamental in various natural phenomena, including gas exchange in lungs and nutrient absorption in cells. Understanding diffusion is essential in fields like biology, chemistry, and environmental science, where it influences various biological and physical processes.