What is the name for the process by which gases spontaneously move from an area of higher concentration to one of lower concentration

The process by which gasses spontaneously move from an are with higher concentration to one of lower concentration is called diffusion. This process mainly occurs in gases and liquids. The end result of diffusion is called dynamic equilibrium. It is a complete mixing of the molecules  of the gas.

The process by which gases move spontaneously from an area of higher concentration (this area has high concentration gradient) to the are of low concentration (this area has low concentration gradient) is called diffusion. Example of it is when a perfume is spread into a room, the molecules of aroma will diffuse from the starting point to the around space because of the difference in the concentration of that molecules.