The photon is an elementary particle and are the quanta of the electromagnetic field. Photons are inherently massless and travel at the speed of light in a vacuum (usually denoted with a
Photons have both a wavelength (denoted symbolically by
^frequency-wavelength-equation
The energy of a photon is related to its frequency (and inversely it's wavelength) by the equations:
^planck-einstein-relation
Despite photons being massless they still have momentum through the energy-momentum relation which can be simplified to the following equation where
^photon-momentum-equation