the.com/electromagnetic spectrum

means The full range of electromagnetic radiation, ordered by wavelength and frequency, from long lazy radio waves to short frantic gamma rays, with visible light as just a thin sliver in the middle.

from 'Electromagnetic' fuses 'electric' and 'magnetic,' recognizing that electricity and magnetism are two faces of one force, a unification sealed by Maxwell's equations in the 1800s showing light itself is an electromagnetic wave. 'Spectrum' comes from Latin for 'appearance' or 'image,' related to 'specere,' to look — the word Newton borrowed when he split sunlight through a prism into its band of colors. Later scientists realized that visible spectrum was just the sliver of a much vaster range, and 'spectrum' stretched to cover the whole family, from radio waves to gamma rays, all ghosts of the same underlying wave.