Neutrinos - fundamental science and applications

Neutrinos are the second most abundant particles in the universe. An understanding of their known properties point to physics beyond the standard model of particle physics. After a brief introduction the Indian effort to contribute in this area and some of the physics issues that the Iron Calorimeter detector for atmospheric neutrinos can address are described. I will also mention some of the reactor based efforts worldwide to search for sterile neutrinos and how such detectors can also be used for remotely monitoring nuclear power reactors. (author)