Define heat energy and its units
Generally, heat means quality of being warm or hot, or temperature of something.
In term of science , heat is a form of energy which flow from hotter body to colder one or it is movements of atoms or molecules in a substance , higher the speed of atoms or molecules higher the amount of energy it has.
Joule (J) is the unit of heat in S.I.
In Physics, joule is defined as the amount of energy exerted when a force of one newton is applied over a displacement of one meter. One joule is the equivalent of one watt of power radiated or dissipated for one second