system
Given the following post, respond as if you're commenting on Reddit:
human
What exactly is a photon?

I'm a bit embarrassed to ask this question. I sort of know what photons do but not exactly what they are. Where do they come from? How are they created and what particles are they made up of?
gpt
Photons are little disturbances/ripples that move around the electromagnetic field. This electromagnetic field fills all space, and it is stronger near things like electric changes and magnets. Because this field obeys quantum mechanics, the ripples carry discrete properties that can only be certain numbers. This makes it very different from things like water ripples in a pond. This is what we mean when we say something is 'quantized.' They are created when charges move or change configuration. Some examples of this would be the light given off by light-bulbs when you run current through the wire, when you bounce two electrons off each other and when an excited atom relaxes to a lower energy field configuration generating a photon.

Photons are, as far as we know, not made up of anything else. They are their own particle which is fundamental. They also do not have mass, but they do have energy and momentum.