Accreting black holes are found in two families of objects: AGN and X-ray binaries. Distant quasars that shaped the early Universe are powered by supermassive black holes. They are, however, difficult to study, as they are usually very faint. X-ray binaries are much brighter and they evolve on much shorter timescales, providing us with perfect laboratories for studying black hole accretion flows. Yet the properties of the accretion flow should be fairly scale invariant, so what we learn about accretion flows from stellar mass systems should also be applicable to the supermassive black holes. I will review recent progress in understanding Galactic binary systems, in particular how the bewildering variety of spectral, timing and jet properties - the so called 'spectral states' - can be explained by changing the nature (and hence geometry) of the accretion flow.