What does the process of diffusion require?
Diffusion is a process which allows particles to move from areas of high concentration to areas of lower concentration.
The process requires that particles are moving. As long as particles are not at a temperature of 0K (absolute zero) they have kinetic energy (energy of movement).
The video below helps to illustrate why the movement of particles makes diffusion possible. This example looks at the process of diffusion occurring across a cell membrane, but it is worth noting that diffusion can also occur without a membrane (perfume diffusing in a room would be an example).
Hope this helps!