Light is a wave (for one), but let’s back up a second and think about what light really is. The “light” we see is a very small slice of something know generally as electromagnetic radiation (EMR). Different kinds of EMR exist because of their wavelength. We’ve talked about wavelength before, and how it’s similar to frequency. Both things mean: how rapidly is the wave waving?
The entire range of possible wavelengths of EMR is called the “spectrum.” The plot above looks complicated, but it’s not. All that’s changing is that waves are rapid at the top and slow at the bottom.
The slice we call “visible light” is shown. The difference between colors is the wavelength of the wave. Radio and TV waves are the exact same thing as visible light, except much longer wavelength. (You could say they are redder than red.) Microwaves, X-rays, gamma-rays … it’s all EMR.
