PLATO 2.0 (PLAnetary Transits and Oscillation of stars) will the the 3rd medium class mission (M3) of the CosmicVision scientific programme of the European Space Agency. It was selected in February 2014,and just adopted in June 2017,with a launch date planned for 2026and six years of operations. PLATO 2.0 will place European researchers, and Spanish ones in particular, at the forefront of exoplanetary science, benefiting from the expertise acquired or to be acquired with precursor missions as CoRot, Kepler, Cheops andTESS, as well as from the development of complementary ground-based facilities for radial velocity measurements of exoplanetary systems candidates (like CARMENES at Calar Alto). The Spanish contributions to the development of PLATO 2.0 are very significant, including the focal plane assemblies and main electronics units (digital processing and power supply), as well as the optical verification in thermal vacuum of 8 out of the 24+2 PLATO 2.0 telescopes. PLATO will the fabrication phasein 2018, after the Preliminary DesignReview to be performed by ESA, with a delivery of the telescopes planned for 2022-2023. PLATO 2.0 will be dedicated to the detailed analysis of exoplanetary systems (including the detection of >10 Earth-like planets in the habitable zoneof Sun-like stars), and to the asteroseismical study of their central stars. Both objectives require ultra-high photometric accuracy of ~3x10-5 and an extensive ground based follow-up observational program to measure the radial velocity curves of the candidate systems. By combining the results from transits, asteroseismology and radial velocities it will be possible to fully characterize exoplanetary systems: orbital periods, density and evolutionary state, starting a new age of comparative (exo-)planetology. PLATO 2.0 will therefore be crucial for placing our own Solar System into a comprehensive context of exo-planetary systems..