The band of electromagnetic radiation with components that are separated into their relative wave lengths. The portion of the spectrum that the human eye can detect is called visible light, between the longer infrared waves and the shorter ultraviolet waves. The various types of energy comprising the spectrum are (from longest to shortest) radio, infrared, visible, ultraviolet, x-rays, gamma rays, and cosmic rays.
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.
Dictionary source: WordNet 2.0
English to English translation of Electromagnetic spectrum
The entire range of electromagnetic radiation . It ranges from the longest wavelength radiation, radio waves, through microwaves , infrared, visible light, ultravolet, x-rays and finally to the shortest wavelength radiation, gamma rays. Although all the forms of electromagnetic radiation propagate at the speed of light , the shorter wavelength radiations carry more energy per photon than the longer wavelength radiations.