Electromagnetic Spectrum:

Visible light belongs to a family of waves known as the electromagnetic spectrum. Other members of this family include high frequency short wavelength gamma rays and X-Rays, ultra violet (UV), infra red (IR) microwave, short/long wave radio waves and down to extremely low frequency electromagnetic (EM) waves for sub-surface detection and imaging.

The individual bands of the EM spectrum are so named because of the historical reasons associated with the discovery of waves with those wavelengths.