Neutrino physics is at the forefront of particle physics. Because of their extremely low cross section for interactions with matter, neutrinos have been and are very valuable probes to investigate the intimate structure of matter constituents as well as well as bodies like our Sun, inaccessible with other methods. Neutrinos play an important role in physics, astrophysics and cosmology. However, despite the big efforts in the past, neutrino properties are not yet completely known; for instance we don't know if they have a mass or a magnetic moment and the symmetry rules they obey.
A better knowledge on these points, will also allow to go beyond the so called standard model of elementary particles and it is essential also for other fields like astrophysics and cosmology. For these reasons, experimental and theoretical searches are very active, involving hundreds of physicists and high level technicians and requiring significant funds. It has to be mentioned that most of the experiments are demanding highly developed technologies in many fields (electronics, informatics, material science). Finally, it has to be mentioned that nowadays, study on possible applications of neutrinos in other fields of science and technologies than those above mentioned are moving their first steps.