The basic point to understand is that light is the mediator of the electro-magnetic force: its the way by which particles with charge interact. In quantum field theory you’d say that what you mean by ‘interaction’ of 2 charged particles is that they exchange a single particle of light (a photon).
Light is what transmits the electric and magnetic forces. So for example when you hold two poles of a magnet close to each other so that you feel a force the two poles are transmitting particles of light from one to another. It’s just that this light is not in the optical part of the spectrum so you can’t see it.
This means that any particle that has a charge will be interacting with light all the time, because it is using the light to say to all the other particles around it “I have a charge!”
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sebstrug commented on :
Thank you for your replies, that was very interesting