What is osmosis and how does it affect cells 2 examples

Osmosis affects cell volume in both plant and animal cells,
sorry this is all i know

Osmosis is the diffusion of water. Diffusion is when cells move to an area of lower concentration through a semi permeable membrane. Osmosis only affects water. It affects water by letting water constantly move from one side of the membrane to the other. When both sides have an equal concentration, the water molecules water still moves around but equilibrium has been reached.

Ithink its because more have died recently than in the past.