What is Passive Transport? Passive transport is a movement of ions and other atomic or molecular substances across cell membranes without need of energy input.
Diffusion is when substances move from an area of high concentration to an area of low concentration, until the concentration becomes equal throughout a space.
Osmosis a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
Facilitated diffusion is the process of spontaneous passive transport of molecules or ions across a biological membrane via specific trans membrane integral proteins.