Diffusion is the spreading of a substance to fill all space available
Diffusion supplies fishes on the bottom of a lake with air; it is responsible for the spreading of odours even without any wind and for the formation of a white solid in the experiment.

Osmosis is diffusion (i.e. of water) through a semipermeable membrane.
Osmosis helps that men and animals do not dry up, that flowers do no wither and that salad keeps crunchy.
Cell membranes are permeable for water (::) , not permeable for nutrients (^) dissolved in it.
Water (::) spreads from a place with high water concentration (outside the egg) to a place with lower water concentration (inside the egg).