The study of cataclysmic variables - interacting binary stars containing a white dwarf accreting from an orbiting companion - is undergoing an exciting renaissance, as it embraces observations at all wavelengths. Cataclysmic variables allow, in particular, the direct and detailed study of equilibrium and non-equilibrium accretion discs; in turn these developments also help in our understanding of X-ray binaries, black holes and active galactic nuclei...