If we compare a cell with an egg there is a major difference between the outer membrane
in case of cell they are bounded by semi permeable membrane
The semi permeable membrane is a selectively permeable membrane which allows the movement of only solvent molecule and not solute molecules through it.
So water can move into or out of the cell through cell membrane by a special physical process known as osmosis.
the water will move from a low concentration gradient to high concentration gradient.