How do the the forces that drive diffusion and osmosis differ?

Diffusion is the movement of all types of substances from the area of the higher free energy to the area of the lower free energy Osmosis is the movement of only solvent or water from its higher free energy or chemical potential to the area of its lower chemical potential when the solute particles are not allowed to diffuse. 

They might be white heads, basically pimples but you should ask your parents to check them out before it’s something bad.