The term 'thermal energy' is used differently, and often loosely, in different contexts. It refers to several distinct physical concepts, such as the internal energy, or as the enthalpy, of a body of matter and radiation; or as heat, defined as a type of energy transfer (as is thermodynamic work); or as the characteristic energy of a degree of freedom,
k
B
T
{\displaystyle k_{\mathrm {B} }T}, in a system that is described in terms of its microscopic particulate constituents, where
T
T denotes temperature and
k
B
k_{\mathrm{B}} denotes the Boltzmann constant.
I learned this last week in my Sci-tech class!
