Final answer:
Water moves through a membrane via osmosis, a type of passive diffusion that equalizes the concentration of solutes on both sides of the membrane.
Step-by-step explanation:
Osmosis is the process through which water moves across a membrane from an area of lower solute concentration to an area of higher solute concentration. It is a type of passive diffusion and does not require energy. Water moves through the membrane to equalize the concentration of solutes on both sides of the membrane. In osmosis, water molecules are facilitated in their movement by aquaporins, specialized transport proteins that act as channels for water.