  The experimental evidences in favor of oscillations of solar (and KamLAND)
and atmospheric (and K2K) neutrinos are briefly reviewed and accommodated in
the framework of three-neutrino mixing. The implications for the values of
neutrino masses are discussed and the bounds on the absolute scale of neutrino
masses from Tritium beta-decay and cosmological data are reviewed. Finally, we
discuss the implications of three-neutrino mixing for neutrinoless double-beta
decay.
