Photons are said to be the quantum (new-Indian-term: प्र-भागी) that carries the energy of unified electromagnetic fields.

An unified field is an advance treatment of electric and magnetic fields that are treated “same” because of a great idea of Einstein’s special theory of relativity. Like the equivalence of space-distance and time-intervals, electric field and magnetic fields are the manifestation of the same “gauge” fields. This is necessary if one observes the electric and magnetic phenomena from a space-point (or frame of reference) which is moving so fast with respect to the highest speeds attainable in our Universe that if something moves even at 1/20th the speed of light differences start to show up in our calculation from so called classical understanding.