What is thermal energy.

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!