Page "Thermodynamics" Paragraph 45

Equilibrium thermodynamics studies transformations of matter and energy in systems at or near thermodynamic equilibrium.

In thermodynamic equilibrium, a system's properties are, by definition, unchanging in time.

In thermodynamic equilibrium no macroscopic change is occurring or can be triggered ; within the system, every microscopic process is balanced by its opposite ; this is called the principle of detailed balance.

A central aim in equilibrium thermodynamics is: given a system in a well-defined initial state, subject to specified constraints, to calculate what the equilibrium state of the system will be.