Light that we can see (“visible light”, “VIS”) is a small part of a spectrum of a thing called “electromagnetic radiation”, distinguished by something we call “wavelength”.
As the wavelength varies in the visible spectrum, the light appearantly changes color from violet to red.
There are no actual boundaries between one range of wavelengths and another. So numbers associated with a certain range are only approximate.
If we explore the spectrum from long wavelengths to shorter wavelengths, we meet :
- “radio waves” : regular broadcast wavelengths are for example 500 meters long, but even longer radio waves exist
- “short waves” : (“Radar waves”, “Millimeter waves”)
- “visible light”
- “ultraviolet light”
- soft x-rays
- hard x-rays
- gamma rays
(C) Wikipedia, file : https://upload.wikimedia.org/wikipedia/commons/c/cf/EM_Spectrum_Properties_edit.svg