Abstract
The evolution of the electron and muon (g-2) experiments is traced. The basic principles of the two types of technique, resonance and precession, are outlined with particular emphasis on the most recent examples which are the latest measurements on the electron and muon, respectively. This discussion of the experiments is set in the framework of the theoretical predictions of quantum electrodynamics and it is shown how the dialogue between theory and experiment has pushed both to the extremes of precision; extremes at which there is nevertheless good agreement.