In galvanic cells, electrons are used as the source of charge difference. This creates a current that we can use for a large variety of purposes (i.e. light up a bulb). When I think about this phenomenon there are several things uncertain to me.
Firstly, how does the electron flow heat up the filament of a light bulb?
Secondly, is this behavior caused because of the electron (so its properties are of essence for electricity) or because of the charge differences?
If the charge difference is the only factor, does this mean that any particle with a charge other than zero will create electricity when it moves?
For example, will a positron generate electricity and heat up a filament?
Can a positron even be directed like an electron? I would suppose that if this was the case, if electrons flow from left to right and so does the current, then if we want the same direction of current flow, positrons should flow the other way.
My only guess as to how light bulbs can produce light would be that electrons somehow transform into photons, but I am unsure of how they do that.
I want to understand why electric current works at a fundamental level. I am not looking for the answer "Electrochemical cells produce a voltage by making the electrons from a spontaneous reduction-oxidation reaction flow through an external circuit.", that many online sources provide. This answer is very unhelpful. I know how the electrons move and how to drive those reactions, but I don't understand why electricity really works.