Neutrino mass and oscillation: An introductory review

After a brief introduction to neutrino mass via the see-saw model I discuss neutrino mixing and oscillation, first in vacuum and then its matter enhan cement. Then the solar and atmospheric neutrino oscillation data are briefl y reviewed. Finally I discuss the problem of reconciling hierarchical neutr ino masses with at least one large mixing, as implied by these data. A mini mal see-saw model for reconciling the two is discussed.