Visible light is the part of the electromagnetic spectrum that can be detected by the human eye. It consists of electromagnetic waves with wavelengths roughly between 380 nanometers (violet) and 750 nanometers (red). These wavelengths correspond to different colors — from violet, blue, green, yellow, and orange, to red — which together form the visible spectrum.
Like all electromagnetic radiation, visible light travels at the speed of light in a vacuum (about 3 × 10⁸ m/s) and carries energy in the form of photons. The color we perceive depends on the light’s wavelength (or equivalently, its frequency): shorter wavelengths have higher frequencies and more energy (violet/blue light), while longer wavelengths have lower frequencies and less energy (red light).
Visible light is essential for vision — objects are seen when they reflect, absorb, or transmit light to our eyes. It also plays a role in processes like photosynthesis in plants, optical communication (fiber optics), photography, and countless technological applications.
In summary, visible light is simply the small slice of the electromagnetic spectrum that our eyes have evolved to detect — our personal “window” into the universe.