Light is made of particles called photons, which are tiny packets of energy that also behave like waves. These photons have no mass but carry energy that depends on their frequency or wavelength. Light exhibits wave-particle duality, meaning it behaves both as an electromagnetic wave and as discrete particles called photons. The energy of each photon is proportional to the frequency of the light, with higher-frequency photons carrying more energy. In an atomic context, photons are emitted when electrons in atoms jump between different energy levels, releasing energy in the form of light. This wave- particle duality was first clearly explained by Albert Einstein in his theory of the photoelectric effect, for which he won the Nobel Prize. Light as an electromagnetic wave consists of oscillating electric and magnetic fields, which support each other as they travel through space. These oscillations occur at right angles to each other and to the direction of wave travel. Thus, light can be described both as waves of oscillating electric and magnetic fields and as particles called photons, depending on the context in which it is observed.
