What are the effects of Brownian motion?

The effects of Brownian motion is seen in our everyday life. The most well-known effect is diffusion, the movement of particles from a region of higher concentration to a region of lower concentration. Many wonder why does diffusion occur and the most common answer is " concentration difference ". the more detailed explanation would be that the particles are constantly being hit by the air particles or water molecules and this causes them to move from their original location to another, causing them to spread in all directions. For example, when one sprays perfume in a corner of the room, the perfume particles in that region is constantly being bombarded by the surrounding air particles and there is no fixed direction. this causes the perfume particle to spread in all directions, or random directions, and soon the whole room is filled with the perfume particles. That is why when someone sprays perfume, the whole room can smell it.