Light is electromagnetic radiation that can be detected by the human eye, typically with wavelengths in the range of about 400 to 700 nanometers, which corresponds to the visible spectrum of colors from violet to red
. More broadly, light refers to electromagnetic radiation of any wavelength, including not only visible light but also gamma rays, X-rays, ultraviolet, infrared, microwaves, and radio waves
. Physically, light exhibits both wave-like and particle-like properties. It behaves as electromagnetic waves-oscillating electric and magnetic fields that travel through space at a constant speed of approximately 299,792,458 meters per second in vacuum (the speed of light)
. At the same time, light can be described as discrete packets of energy called photons, which are massless particles carrying quantized energy
. Light is fundamental for vision, allowing us to perceive the world by reflecting off objects and entering our eyes. It also plays critical roles in natural processes such as photosynthesis, warming the Earth, and enabling astronomical observations that reveal the universe's structure and history
. The visible light humans see is only a small part of the electromagnetic spectrum, with ultraviolet and infrared light just beyond human vision
. In summary, light is electromagnetic radiation that transfers energy through space, perceived by humans primarily as visible light, but encompassing a vast range of wavelengths beyond what the eye can detect
