Light is used and manipulated to create lasers, holography and fiberoptic telecommunications systems, but it is primarily used in both scientific communities and in the world to make it possible for people to see when the sun is not out or the room is dark. Light is electromagnetic radiation that can be seen by the human's naked eye.
Light transmits both spatial and temporal information. Lights are also the basis for the field of optical communications and optics. The theory of light and its properties can be derived from the classical theory of electromagnetism. This theory describes light as coupled electric and magnetic fields that move through space and travel as a wave. Quantum theory details light as being made up of discrete packets of energy known as photon.
The wave theory of electromagnetism and the quantum theory reveal only one nature of light, but light is a dual nature. In quantum mechanics the wave-particle duality is observed and explained. In the mid-20th century, scientists discovered and wrote a comprehensive theory on light. This theory was known as quantum electrodynamics and it considered to be the complete theory of light according to physicists. This quantum electrodynamics theory is a combination of quantum mechanics, wave electromagnetism and the theory of relativity.