write this in a short sentence
Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration until equilibrium is reached. In the context of a hypotonic solution, the concentration of solutes outside the cell is lower than inside the cell, causing water to move into the cell. In a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell, causing water to move out of the cell. Equilibrium is reached when the concentration of molecules is the same inside and outside the cell.
2) Diffusion and osmosis are both types of passive transport, where molecules move from an area of high concentration to an area of low concentration. The main difference is that osmosis specifically refers to the movement of water molecules across a selectively permeable membrane. The only substance that undergoes osmosis is water.
3) Active transport requires energy input to move molecules against their concentration gradient, from an area of low concentration to an area of high concentration. Passive transport, on the other hand, does not require energy as it involves moving molecules along their concentration gradient, from an area of high concentration to an area of low concentration. Active transport methods include ion pumps, endocytosis, and exocytosis, while passive transport methods include diffusion, facilitated diffusion, and osmosis.