What are the similarities between diffusion and osmosis?

Both osmosis and diffusion work to balance the concentration between two solutions. They are both forms of passive transport (no energy required) and in each process particles move from areas of higher concentration to areas of lower concentration. Thus, they both depend on a concentration gradient to drive the movement of particles. The movement of particles in both processes is due to their random thermal motion. Additionally, both diffusion and osmosis become more effective over time as the system approaches equilibrium.