What Is Light?

1. Division by light source

Based on this classification, light is divided into the following categories:
– Natural light produced by the sun will be called sunshine (also known as white light, consisting of many monochromatic lights capable of continuously varying from red to purple).
– The natural light produced by the moon that we can see with our naked eyes is the actual light. This is the light generated by the sun shining on the moon and then reflected back to the human eye
– The artificial light produced by lamps is called lamplight.
– The light emitted by animals will be called biological light.

2. Wavelength-division

Based on this factor, light is classified into the following types:
– Cold light: These are light whose wavelengths are concentrated near the violet spectrum.

– Hot light: Light whose wavelength is near the red region . Wave or Particle?

One of light’s seemingly paradoxical features which has been debated for millennia is that sometimes it appears to act like a wave of energy and, at other times, like a collection of discrete particles. Let’s look at each definition and how they interact with each other.



An important characteristic of the wave nature of light is its wavelength. The wavelength is the distance over which the electromagnetic fields associated with the light wave repeat themselves, like the distance between crests of waves in an ocean. The wavelengths of light are tiny, typically between 450 and 650 nanometers! As seen in the figure below, red light has the longest wavelength of visible light, and blue has the shortest.