Recent experimental developments established that at least two of the neutrinos have masses, hence they can have electromagnetic interactions through loop diagrams. I first illustrate the prediction of the Standard Model, minimally extended to allow massive neutrinos, for the electron neutrino magnetic moment measured at the reactors. I will then elaborate on the effects of light sterile neutrinos on the measured effective electron neutrino magnetic moment and the physics of the Early Universe when Majorana neutrinos possess transition magnetic moments. The Majorana versus Dirac nature of neutrinos remains an open question. Since Majorana neutrinos can behave quite differently from Dirac ones when they are non-relativistic, I will discuss recent results showing the angular distribution of the daughters in the decay of a heavy neutrino into a lighter one and a self-conjugate boson is isotropic in the parent’s rest frame if the neutrinos are Majorana, independent of the parent’s polarization. I will show that this result follows from CPT invariance and is independent of the details of the physics responsible for the decay.