Heat can move in one of three ways. In conductance, the heat passes trough something solid, such as wood or metal. This process is pretty slow. Another way heat moves is radiation . In radiation, the heat passes directly through space in the form of photons, tiny packets of energy travelling at the speed of light.
Radiation is the way that the sun's warmth reaches Earth.
Finally there's convection . In convection, heat warms the air. Convection is the reason stars twinkle. When air heated by convection rises, it tumbles and swirls. That's why the air shimmies over a fire or a radiator.