Light, or visible light, is electromagnetic radiation of a wavelength that is visible to the human eye (about 400–700 nm). In a scientific context, the word light is sometimes used to refer to the entire electromagnetic spectrum.[1] Light is composed of elementary particles called photons.

Three primary properties of light are:

Light can exhibit properties of both waves and particles. This property is referred to as wave-particle duality. The study of light, known as optics, is an important research area in modern physics.

  1. "What Is a Light Source?". 
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