I present the results from the first detection of gravitational waves and light from the same cosmic source, GW170817. GW170817 is the merger of two neutron stars, detected in Gravitational Waves (GWs) by Advanced LIGO/Virgo on August 17, 2017. The GW detection was followed by the discovery of electromagnetic emission across ten orders of magnitude in wavelength, which allowed the localization of GW170817 to a galaxy in our own cosmic neighborhood. In this colloquium I will present the results from the first successful hunt for electromagnetic radiation from a GW source across the electromagnetic spectrum, from the X-rays to the radio band. I discuss the open questions raised by GW170817 and the bright future ahead for multi-messenger Astrophysics.