The neutrino probability to interact is so faint that every attempt to detect the neutrino signal is an experimental challenge. Neutrinos freely escape from remote galaxies or from the deep of the Sun and they are natural carriers of precious information about regions otherwise unaccessible. Borexino is a large, unsegmented liquid-scintillator calorimeter built in the Laboratori Nazionali del Gran Sasso (LNGS) in Italy with the ambitious goal to study in real-time energy the single components of the solar neutrino spectrum. The record-low level of radioactive purity made possible to achieve an exceptional sensitivity especially at energies close and below few MeV. This contribution is aimed at reviewing the most important Borexino results and to discuss the future perspectives, emphasizing in particular the unique possibility of Borexino to aggress the measurement of the elusive CNO-neutrino component and to exploit the possible existence of a fourth sterile neutrino (SOX project).