Heat transfer

Heat transfer is the way the heat moves from one physical system (or body) to another. Heat transfer requires a difference in temperature.^[1] Heat moves from the hotter body (higher temperature) to the colder one (lower temperature).^[2] The bodies in question may be in a solid state, a liquid state or a gaseous state.^[2] There are three modes of heat transfer: conduction, convection and radiation.^[1]