Conduction, where particles within a conductor gain energy as they heat up and vibrate more vigorously passing energy onto adjacent particles as they collide. Convection, which only occurs in fluids, as fluids gain energy they become less dense as the particles move more quickly and away from each other so rise up within the fluid, as they cool they lose energy becoming more dense and fall back down forming convection currents. Finally radiation, objects emit infrared radiation which transfers heat without matter and is absorbed by other objects, matte black surfaces are the best emitters and absorbers of radiation.