A microscopic perspective, in statistical thermodynamics the entropy is a measure of the number of microscopic configurations that are capable of yielding the observed macroscopic description of the thermodynamic system:

S=KBln Ω

where Ω is the number of microscopic configurations, and KB is Boltzmann's constant. It can be shown that this definition of entropy, sometimes referred to as Boltzmann's postulate, reproduces all of the properties of the entropy of classical thermodynamics(shahbaz)

• The Boltzmann constant (kB or k), named after Ludwig Boltzmann, is a physical constant relating energy at the individual particle level with temperature.

• It is the gas constant R divided by the Avogadro constant

• It has the same dimension (energy divided by temperature) as entropy. The accepted value in SI units is 1.3806488(13)×10−23 Joule/degree K

• For more information refer to link below.