What is the differences and simalarities between diffusion and osmosis?

Diffusion may be simple, whereby solutes travel through the phospholipids in the cell membrane as they have the same polarity as a lipid or are small enough to do so.Or, diffusion is faciliated and this is where the molecule are too large or have an opposite polarity to a lipid so must travel across the cell membrane via a transport protein. In contrast, osmosis is the movement of water across a semi permeable membrane from a high solute concentraion to a low solute concentration- this is also known as a water potential gradient. Diffusion is similar to osmosis as the molecules move down a concentration gradient and both processes are passive, which means they don't require any energy (no ATP is used up).