The Diffusion Equation is a mathematical formula that describes how substances spread over time. It is commonly used in fields like physics, chemistry, and biology to model processes such as heat transfer, pollutant dispersion, and the movement of molecules in a medium. The equation helps predict how the concentration of a substance changes in space and time. In its simplest form, the Diffusion Equation can be expressed as a partial differential equation. It relates the rate of change of concentration to the spatial distribution of that concentration, often incorporating factors like diffusion coefficients that characterize how quickly a substance diffuses through a material.