Neutrino masses, mixing and oscillations

Neutrino mixing and the basics of neutrino oscillations in a vacuum are considered. Recent evidence in favor of neutrino oscillations, obtained in solar and atmospheric neutrino experiments, are discussed. Neutrino oscillations in the solar and atmospheric ranges of Δm² are considered in the framework of the minimal scheme with the mixing of three massive neutrinos. Experiments on the measurement of neutrino mass via investigation of the high-energy part of the β-spectrum of tritium and experiments on the search for neutrinoless double β-decay are also discussed.