What is osmosis and how is osmosis different from diffusion? if ion transport requires atp, what type of transport is that and give an example?

Osmosis means the net movement of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane.

Osmosis is different to diffusion as osmosis is only about the movement of water molecules, while diffusion can be the movement of any dissolved substances. Including gas or liquid.

If a transport requires atp, a type of energy, its active transport. Only active transport requires extra energy.

Another example of active transport includes the absorption of nutrients in small intestine.