Water transportation across a lipid membrane can occur through facilitated diffusion, but it is not typically considered osmosis. Osmosis specifically refers to the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration, without the need for energy or a transport protein.
Facilitated diffusion, on the other hand, involves the movement of molecules across a membrane with the help of specific transport proteins. While water can move through these proteins (such as aquaporins), this process is still driven by the concentration gradient and does not require energy, similar to osmosis. However, the key difference is that facilitated diffusion involves the use of transport proteins, whereas osmosis does not.
In summary, while water can move through facilitated diffusion via transport proteins, this process is not classified as osmosis. Osmosis is a specific type of passive transport that does not involve transport proteins.