  A brief overview of the important theoretical issues in neutrino physics is
presented and some of the current ideas for addressing them in the framework of
the seesaw mechanism of neutrino masses are discussed. Among the topics
discussed are ways to understand maximal mixing pattern among the three
neutrino species, both uni-maximal and bimaximal kinds. Constraints from
baryogenesis on mixing patterns are noted. In the last section, the question of
understanding the small masses for sterile neutrinos, which seem to be needed
for various reasons is addressed.
