Osmosis
Osmosis is a special kind of diffusion that only involves water moving through a selectively permeable membrane. During osmosis, water moves from an area of higher concentration to an area of lower concentration of water through a selectively permeable membrane. So lets not get confused, diffusion is when the solute particles mix with the water particles. Osmosis is when water mixes with the solute particles. For the cell, water passes through a selectively permeable membrane which is the cell membrane. Using a plant as an example, with no water in the soil, the would not be any water to move through the cell. Then the cell would get any nutrients and it can die. When you water a plant, Osmosis takes place by moving the water particles to the cell so the cell can get it's nutrients. Sometimes the process of osmosis depends on the difference in the concentration of cells. If the concentration of the water particles in the cell is higher than outside, water particles will exit the cell. If the concentration of water particles outside the cell is higher, the water particles will move inside the cell.