I'm reading about detectors and seeing the term "electromagnetic energy resolution", but can't find a definition. Is this simply referring to the resolution of the energy of electrically charged particles? Or could it be to do with the resolution achievable through a particular method of detection, for example, measuring ionization charge rather than Cerenkov light (not that photons are any less 'electromagnetic' than electrons really, but whatever) ? Or something else? And will it typically be referring to the energy that the particle actually has, or the detectable energy that it has deposited?