How are osmosis and diffusion alike?
Diffusion is the process of where a substance moves from an area of high concentration to an area of lower concentration. Diffusion doesn’t need a membrane.
Whereas, osmosis is a special kind of diffusion in which water moves through a selectively permeable membrane from an area of high concentration to an area of low concentration.
Here is a video which describes how osmosis impacts onion cells placed into tap water and then into a salt water solution.
Hope this helps!