>Another way to view it: When light is emitted, it is quantized (discrete). It is not continuous. When you turn the dimmer switch on an LED, it doesn't produce a bigger or smaller light beam, it produces a larger or smaller number of photons. Each electron you pass through the LED excites an electron to later decay back to ground state.

Though there is also the other way of altering the energy content of a photon, by impacting its frequency (and by extension wavelength.) It's just not useful for affecting the intensity of visible light.

Since we're explaining the photon's essence, I figured making that explicit might help to avoid further confusion.