Note that Facilitated diffusion , Active transport and Osmosis are three different ways of transporting substances across the cell surface membrane.
Facilitated diffusion is the movement of a substance from high to low concentration , similar to simple diffusion , but due to the complexity of the cell surface membrane , polar molecules and ions cannot just pass like that , so they pass through specific carrier and channel proteins in the cell surface membrane and so we call it facilitated diffusion.
For Active transport , it's the movement from low to high concentraion using energy from ATP
For Osmosis , it's totally different . You only name osmosis when its all about water . Its the net movement of water from high water potential to low water potential through partially permeable membrane .
If you're doing AS , you'll be familiar with Endosmosis and Exosmosis.
