The fields vibrate at right angles to the direction of movement of the wave, and at right angles to each other. Because light has both electric and magnetic fields, it is also referred to as electromagnetic radiation . Figure 1 Light waves come in many sizes. The wavelengths of the light we can see range from 400 to 700 billionths of a meter. But the full range of wavelengths included in the definition of electromagnetic radiation extends from one billionth of a meter, as in gamma rays, to centimeters and meters, as in radio waves .
Light is one small part of the spectrum.
Light waves also come in many frequencies. The frequency is the number of waves that pass a point in space during any time interval, usually one second. The frequency of visible light is referred to as color , and ranges from 430 trillion Hz, seen as red, to 750 trillion Hz, seen as violet. Again, the full range of frequencies extends beyond the visible spectrum, from less than one billion Hz, as in radio waves, to greater than 3 billion-billion Hz, as in gamma rays. As noted above, light waves are waves of energy.