Radiant emittance refers to the amount of energy radiated from a surface or object. Synonyms for radiant emittance are often related to the concept of heat and energy transfer. These can include terms such as heat flux, radiant heat, thermal radiation, energy emission, and heat output. Other synonyms may include radiant energy, luminous intensity, and radiant power. Each of these terms relates to the concept of energy transfer, and can generally be used interchangeably with radiant emittance. Whether discussing thermal energy, light, or other forms of electromagnetic radiation, these terms all describe the amount of energy radiated or emitted by a source.