  While until recently they were often considered as exotic objects of dubious
existence, in the last decades there have been overwhelming observational
evidences for the presence of stellar mass black holes in binary systems,
supermassive black holes at the centers of galaxies, and possibly,
intermediate-mass black holes observed as ultraluminous X-ray sources in nearby
galaxies. Black holes are now widely accepted as real physical entities that
play an important role in several areas of modern astrophysics.
  Here I review the concluding remarks of the IAU Sympposium No 238 on Black
Holes, with particular emphasis on the topical questions in this area of
research.
