Gas diffusion is the process by which gas molecules spread from areas of high concentration to areas of low concentration. This movement occurs due to the random motion of molecules, driven by their kinetic energy. An everyday example of gas diffusion is the way the smell of perfume spreads in a room, gradually filling the space as the molecules move outward. The rate of gas diffusion is influenced by factors such as temperature, pressure, and the molecular weight of the gases involved. According to Graham's Law, lighter gases diffuse faster than heavier ones, which is crucial in various applications, including respiration and industrial processes.