SCIENCE (Biology)

Particles move about randomly, and after a bit they end up evenly spreading.

"Diffusion" is just the gradual movement of particles from places where there are lots of them to places where there are fewer of them. 

DIFFUSION IS THE SPREADING OUT OF PARTICLES FROM AN AREA OF HIGH CONCENTARION TO AN AREA OF LOW CONCENTRATION.

Diffusion happens in soloutions and gases.

For example, the smell of perfume diffuses…