Energy
There are multiple types of energy. Theres thermal, mechanical, hydro powered, kinetic, potential, and the list goes on. Thermal energy is the total kinetic energy of particles. Thermal means heat, so thermal energy deals with heat. Thermal energy also relies off of the number of particles. The more particles that are in something, the more thermal energy can be present. Thermal energy works by accelerating the particles within something and the friction caused by the particles produces an exothermic reaction producing heat or thermal energy. When the particles move faster they also move apart. This is called thermal expansion. Thermal expansion is the increase in volume that results from the increase of temperature.