A parameter (thermodynamics) is a variable that describes the thermodynamic state.
Thermodynamic parameters are different in
Intensive parameters indicate an intensity, so do not change if the system increases or decreases. Examples are temperature T, pressure p, chemical potential μ, magnetic field B and electrical potential V. Typically, but not always, intensive lowercase parameters are noted.
Extensive parameters provide a measure of the amount of something. This will change if the system becomes bigger or smaller. Examples are entropy S, volume V, number of moles n, magnetic moment μ and electric charge q. Typically, but not always, extensive capital letters are listed.
Energy is always the product of an extensive parameter and its associated intensive parameter. The different energy concepts of thermodynamics are mathematical functions of the relevant thermodynamic parameters:
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