Osmosis is the movement of water molecules through a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration. This process is essential for maintaining cell turgor pressure and overall homeostasis in living organisms. It allows cells to absorb water and nutrients while expelling waste products. In plants, osmosis plays a crucial role in the uptake of water from the soil, which is vital for photosynthesis and nutrient transport. In animal cells, osmosis helps regulate fluid balance, ensuring that cells neither swell excessively nor shrink, which can lead to cellular dysfunction.