  We review current understanding of the population of radio galaxies and
radio-loud quasars from an observational perspective, focusing on their
large-scale structures and dynamics. We discuss the physical conditions in
radio galaxies, their fuelling and accretion modes, host galaxies and
large-scale environments, and the role(s) they play as engines of feedback in
the process of galaxy evolution. Finally we briefly summarise other
astrophysical uses of radio galaxy populations, including the study of cosmic
magnetism and cosmological applications, and discuss future prospects for
advancing our understanding of the physics and feedback behaviour of radio
galaxies.
