what is light

Light is a form of energy which is referred to as electromagnetic radiation visible to the human eye and is responsible for the sense of sight.Visible light is usually defined as having a wavelength from the range of 400 nanometres (nm), or 400×10−9m,to 700nanometres between the infrared,with longer wavelengths and the ultraviolet,with shorter wavelengths.Like all types of light,visible light is also emitted and absorbed in tiny "packets" called photons,and exhibits properties of both waves and particles.This property is referred to as the wave–particle duality.The study of light is known as optics.