The document discusses the three main methods of heat transfer: conduction, convection, and radiation. Conduction involves the transfer of heat through direct contact of particles. Convection involves the transfer of heat by the circulation of fluids like gases and liquids. Radiation involves the transfer of heat through electromagnetic waves and does not require a medium. An example is given of each method - conduction through a metal strip, convection in ocean currents, and radiation from the sun to earth.