What is Osmosis?

Osmosis is the diffusion of water molecules across a partially permeable membrane, from an area of high water concentration to an area of low water concentration. For exam if you're on the tube you will go to the area of the tube with the most space so you can feel comfortable. Water molecules like to do the same thing so they will move to area where there is more space so they are not packed. And this happens across our cell membrane and the cytoplasm surrounding cells till there is an equilibrium