Simply is the of water particles whilst the term diffusion is used for any other chemicals/substances.
Diffusion in general refers to the net movement of any particles through a semi – permeable membrane whilst osmosis involves specifically the movement of water particles through a semi – permeable membrane.
Whilst there are common factors that affect both diffusion and osmosis such as temperature surface area and concentration gradient; factors such as pressure and affect osmosis specifically.
Hope this helped 🙂