The Standard Model predicts neutrinos to be massless. However the observation of neutrino oscillations clearly established that neutrinos are massive. In the last 20 years there has been a tremendous experimental progress. From the first discovery neutrino oscillations experiments are making precision measurements of the leptonic mixing parameters and the neutrino mass squared differences. I have worked on different aspects of neutrino physics including model building and phenomenology of neutrino mass models, models of flavour in the lepton sector and quantum corrections.