Advanced LIGO and Advanced Virgo have now completed three observing runs, and they are progressing toward their design sensitivities. Many binary black hole mergers have been observed. The observation of the merger of a binary neutron star system has seen the beginning of gravitational-wave multi-messenger astronomy. Neutron star - black hole binaries have also been observed. The fourth observing run for Advanced LIGO and Advanced Virgo, O4, will begin in late 2022. With the improved detector sensibilities there will surely be many more detections, and maybe even the unexpected. Further multi-messenger events should happen, maybe even including high energy neutrinos. Some history of gravitational waves and gravitational-wave detectors will be given. The most interesting results from the latest observing run, O3, will be discussed. A summary of possibilities for future observations by Advanced LIGO and Advanced Virgo will be presented. Future gravitational-wave detectors, like LISA and Einstein Telescope, will also be introduced.