What is the difference between diffusion and active transport?

Diffusion is passive (doesn't need use energy as ATP) where as active transport is active (by hydrolysis of ATP )
Diffusion is down a concentration gradient (from are high conc to low conc) where as active transport goes against concentration gradient (from low conc to high conc)
Molecule can diffuse through the cell membrane (phospholipid bilayer *) where as active transport used carrier proteins in cell membrane for molecules to pass through. *Can explain the meaning of this if your not sure