Hello i have a little clarification to make for myself with the help of you:) So we know that electricity moves so fast through the wires because the charge is being "pushed" by the EM force which is mediated by the photon. Now AC systems no matter what the frequency have real photons mediating their respective EM fields because the voltage and current is reversing polarity constantly. Now in a DC system we say there are virtual photons. Now let's assume a situation you have a 12v DC source , you have a switch and a light bulb. At the moment when you flip the switch "ON" the charge starts to flow in the wire that is after the switch , now in that moment the electrons from a random movement join in a flow of electrons in one direction. Now it is the moment when the system get's connected that the changes happen and in that moment are there real photons involved and if so then for how long? For the moment when the voltage get's "kicked" in the circuit.Because after it is connected it just flows and being a dc circuit we would say it doesn't change polarity is not time/amplitude varying so is constant and has virtual photons right? The same thing goes for SMPS where the high power mosfets actually rapidly switch dc ON/OFF at a very fast rate and that creates a time/amplitude varying current which has real photons and to a certain extent can be considered an AC waveform. So when I flip a dc hand switch at the moment when the power is connected the system has virtual or real photons? Excuse me for this messed up explanation of my question I just am in a hurry.