Page "Statistical mechanics" Paragraph 1

Statistical mechanics provides a molecular-level interpretation of macroscopic thermodynamic quantities such as work, heat, free energy, and entropy.

It enables the thermodynamic properties of bulk materials to be related to the spectroscopic data of individual molecules.

This ability to make macroscopic predictions based on microscopic properties is the main advantage of statistical mechanics over classical thermodynamics.

Both theories are governed by the second law of thermodynamics through the medium of entropy.

However, entropy in thermodynamics can only be known empirically, whereas in statistical mechanics, it is a function of the distribution of the system on its micro-states.