Where is Brownian motion applied?

Brownian motion is the random, uncontrolled movement of particles in a liquid as they constantly collide with other molecules. Brownian movement is partially responsible for facilitating the movement of bacteria that do not encode or express a motility function, such as streptococci. Brownian movement can also influence “deliberate” movement, which is manifested by the naturally motile bacteria that feed the flagella. Brownian motion is commonly used to describe the motion of molecules or suspended particles in a liquid, and its modified versions are also used as models in polymers.