Diffusion is a spontaneous movement of particles from an area of high concentration to an area of low concentration. ...

Osmosis is the spontaneous net movement of water across a semipermeable membrane from a region of low solute concentration to a more concentrated solution, up a concentration gradient.

DIFFUSION refers to the movement of any chemical from one place to another. Diffusion is also the movement of molecules — solute or particles.

They move from a region in which they are in higher concentration to regions of lower concentration. A good example of diffusion is food colouring.

If you place a drop of red food colouring in a beaker of water eventually the entire beaker of water will have a red tint. The food colouring moved through the water until it was equally distributed throughout the beaker. Diffusion takes place along a concentration gradient. A concentration gradient exists until the diffused substance is evenly distributed.

The other everyday examples of diffusion:

Sugar will diffuse through tea until the entire cup of tea is sweet. We stir to speed up the process.The odour of food cooking diffuses through the kitchen. If you open the kitchen door it will spread through the next room.The movement of these molecules is said to be passive. No energy needs to be provided. The natural kinetic energy of the particles supplies the energy..

OSMOSIS exclusively refers to the movement of water across a membraneis a special example of diffusion. It is the diffusion of a substance through a semipermeable membrane from a more dilute solution to a more concentrated solution. This process is also passive since no external energy is needed.

A semipermeable membrane is a barrier that permits the passage of some substances but not others. Cell membranes are described as selectively permeable because not only do they allow the passage of water but also allow the passage of certain solutes (dissolved substances).

Some examples of osmosis:

Absorption of water by plant roots.Reabsorption of water by the proximal and distal convoluted tubules of the nephron.Reabsorption of tissue fluid into the venule ends of the blood capillaries.Absorption of water by the alimentary canal — stomach, small intestine and the colon.