Photons: While electromagnetic waves are waves, they have a particle-like nature. Photons are the particle-like components of electromagnetic waves. In addition, there are three fundamental postulates in the photon model of electromagnetic waves: Photons are isolated, massless units that make up electromagnetic waves. In vacuum, a photon flies at the speed of light . Each photon has energy, which is determined by:
where f is the wave's frequency and h is Planck's constant, a universal constant. Its value is , A continuous electromagnetic wave has the properties of a superposition of a large number of photons.