The Jiangmen Underground Neutrino Observatory (JUNO) is a neutrino oscillation experiment with a 53 km distance from reactors and a 700 m overburden, currently under construction in South China. The primary goal is to measure the neutrino mass ordering with better than 3$\sigma$ after 6 years of data taking. Therefore 20 kton high transparency liquid scintillator, high coverage (75%) of photomultiplier tubes and low backgrounds are needed to achieve an energy resolution of 3% at 1MeV and a calibration accuracy better than 1%. This is the most challenging design in the present reactor neutrino experiments throughout the world. Such a large detector also has a huge potential to measure with sub-percent accuracy three neutrino oscillation parameters and detect neutrinos from various terrestrial and extra-terrestrial sources. This talk will present the status and progress of the JUNO detector and of Taishan Antineutrino Observatory (JUNO-TAO), a satellite experiment of JUNO, designed to measure the reactor antineutrino spectrum with sub-percent energy resolution and provide a reference spectrum for future reactor neutrino experiments.