Blackbody radiation is a concept used to analyze thermal radiation in idealized systems. This model applies if a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium. Planck's law describes the spectrum of blackbody radiation, and relates the radiative heat flux from a body to its temperature. Wien's displacement law determines the most likely frequency of the emitted radiation, and the Stefan–Boltzmann law gives the radiant intensity. Where blackbody radiation is not an accurate approximation, emission and absorption can be modeled using quantum electrodynamics (QED).