A second generation interferometer for the VLTI (Very Large Telescope Interferometer) is beeing established in the Cerro Paranal Observatory, in the south of Chili. The main aim of GRAVITY, working in infrared, is to improve the spatial resolution. GRAVITY consists in a two beam combination of fields of view, one is the scientific field of view, the second allow to correct the atmospheric turbulence. Up to now it can reach some 10" in the near infra-red. The first light was obtained in may 2016, coupling the four UT (Unit Telescopes - diameter 8.20m) telescopes and was succeded by regular missions. A complete description of this new interferometer and its first results are shown in this paper. With this new generation, instruments can study stars closer to the Galactic central black body allowing a better knowledge of the study of physics in the vicinity of black holes, and further tests of General Relativity.