Answer:
Simple diffusion
Step-by-step explanation:
Water moves from one side to the other in a membrane by osmosis, because it is a small particle, so doesn´t need a carrier to pass trough the membrane, and also, the water moves in favor of the gradient, that means, it moves from one side to another to equilibrate it concentration.
Simple diffusion is a similar process, the difference is that this is used by bigger molecules but not by water.
Hope this info is useful .