The Borexino detector, located in the Gran Sasso National Laboratory in Italy, has been designed for real-time spectroscopy of low-energy solar neutrinos. It is also capable to register geo-neutrinos and neutrinos from artificial sources. In Phase I of the experiment lasting for three years between May 2007 and May 2010, we performed the first independent measurements of 7Be, 8B and pep solar-neutrino fluxes, as well as the first measurement of antineutrinos from the Earth. After a dedicated purification campaign of the liquid scintillator in 2011 Borexino entered into Phase II, which allowed to investigate the seasonal modulation in the 7Be signal, to study the cosmogenic backgrounds and to update the measurement of the geo-neutrinos. Within Borexino a new project SOX is also under development. It is devoted to search for sterile neutrinos via the use of a 51Cr neutrino source and a 144Ce-144Pr antineutrino source placed in close proximity of the detector active volume.