What is the kinetic theory of gases? How is it useful?

(N/A) The approach by which the macroscopic properties of gases can be explained at a microscopic level is called the kinetic theory of gases. In the $19^{th}$ century,scientists like Maxwell,Boltzmann,and others developed this theory.
Kinetic theory of gases explains the pressure and temperature of gases in terms of the motion and collisions of molecules.
It incorporates the gas laws and Avogadro's hypothesis.
Kinetic theory of gases relates measurable macroscopic properties of a gas,such as viscosity,pressure,temperature,internal energy,heat capacity,specific heat,conduction,and diffusion,with molecular parameters. From this,the estimation of molecular size and mass can be performed.