The recent detections of gravitational waves from merging black holes and neutron stars have established gravitational waves as a new cosmological messenger and opened unique opportunities for probing gravity and matter in unexplored regimes. I will discuss the basic physics of gravitational waves, the facilities and methods for detecting and interpreting the signals, and the remarkable insights we have gained from the observations to date. I will conclude with an outlook onto the exciting prospects and challenges for the next years as the field of gravitational wave physics moves from the discovery era to one of precision physics.
