Answer:
Diffusion
Step-by-step explanation:
Diffusion and Facilitated diffusion are the only two passive transports present. The other would be the active transport.
The differences between diffusion and facilitated diffusion is that diffusion is the substance passing through a phospholipids (lipid bilayer), while facilitated diffusion uses proteins in the bilayer that will allow this substance to pass through.
Like in the diagram shown, we start off with a high concentration on the top of the lipid bilayer, but we want to have both sides equal. That's why diffusion happens where at the end both concentrations on each side are equal.