  This brief conference proceeding attempts to explain the implications of the
anti-de Sitter/conformal field theory (AdS/CFT) correspondence for black hole
entropy in a language accessible to relativists and other non-string theorists.
The main conclusion is that the Bekenstein-Hawking entropy S_{BH} is the
density of states associated with certain superselections sectors, defined by
what may be called the algebra of boundary observables. Interestingly, while
there is a valid context in which this result can be restated as "S_{BH} counts
all states inside the black hole," there may also be another in which it may be
restated as "$S_{BH}$ does not count all states inside the black hole, but only
those that are distinguishable from the outside." The arguments and conclusions
represent the author's translation of the community's collective wisdom,
combined with a few recent results. For the proceedings of the
WE-Heraeus-Seminar: Quantum Gravity: Challenges and Perspectives, dedicated to
the memory of John A. Wheeler.
