A solution is described as "hypotonic" when it has a lower concentration of solutes compared to another solution, typically inside a cell. This difference in concentration causes water to move into the cell through a process called osmosis, leading to cell swelling. If too much water enters, the cell may eventually burst. In biological contexts, red blood cells are often used to illustrate hypotonic solutions. When placed in a hypotonic solution, these cells absorb water and can swell, which may result in hemolysis, the rupture of the cell membrane. Understanding hypotonic solutions is important in fields like biology and medicine.