English: The expected flavour composition of the reactor neutrino flux, for neutrinos of 4 MeV energy used as an example, is plotted as a function of distance to the reactor cores. The fraction of neutrino flavours is calculated on the basis of the neutrino oscillation theory introduced in Box 1. Reactor neutrino oscillation experiments are placed at different baselines to measure the oscillation features driven by different mechanisms. The experiments are usually categorized as follows: very short-baseline (L∼10 m); short-baseline (L∼100 m); kilometre-baseline (L∼1 km); medium-baseline (L∼50 km); and long-baseline (L>100 km) experiments. Details of the past and future reactor experiments, their goals and achievements are the main topics of this Review.