Thermal energy is used for cooking, producing electricity and heating homes and businesses. Although it is used in these ways, it is not the same as heat because heat is transferred when there is a temperature difference between two systems or substances.
Thermal energy is always internal. Thermodynamics is the branch of physics that studies heat and temperature, especially caused by thermal energy. Thermal energy, and in turn thermodynamics, is widely used in science and engineering.Learn more about Thermodynamics