Neutrinos in physics and astrophysics

An elementary general overview of the neutrino physics and astrophysics is given. We start by a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and we introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed as well as the major role they play in astrophysics and cosmology.