In sound waves, the amplitude determines the volume of the sound, and the wavelength determines the pitch.
Similar to pitch, the wavelength of an light wave (i guess an electromagnetic wave?) determines the hue of the light: what color it is, or where it falls on the electromagnetic spectrum.
So that’s what the wavelength correlates to. What about the amplitude?
In: Physics
The intensity/brightness. If you have a high amplitude low frequency light, then you have a bright red light. If you have low amplitude high frequency light, you have a dim blue light.
My favorite example of the difference between these two quantities is the photoelectric effect. Basically shining a light onto the surface of a piece of metal ejects electrons from the metal. There is a certain energy threshold that depends on the type of metal which must be overcome in order for the electron to jump. The amplitude of the incoming light wave corresponds to the number of photons “hitting” the metal while the frequency corresponds to the energy of each individual photon comprising the wave. If you keep the frequency constant and increase the amplitude of the light wave, the energy of each photon remains the same but the number of photons increases. The reverse situation would hold the number of photons constant but increase the energy of each individually.
The amplitude of the wave correlates the the strength of the electric and magnetic fields. The wavelength correlates to how far you have to move to get from one region of maximum voltage to the next.
The amplitude coupled to the frequency gives you an energy density. How much energy is in a cubic meter of light at a given amplitude and frequency.
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