ABSTRACT
For a long time it was believed that the neutrinos are massless fermions. Experiments were consistent with zero mass of neutrinos, although each experiment had its error bar. Around 1970 or so, astrophysical and cosmological motivations for neutrino mass were felt. Around the turn of the millennium, the existence of neutrino masses was firmly established, although the mass values are not quite known yet. In this chapter, we will discuss theoretical and experimental ramifications of neutrino mass.
