  In this short essay we review the arguments showing that black hole entropy
is, at least in part, ``entanglement entropy", i.e., missing information
contained in correlations between quantum field fluctuations inside and outside
the event horizon. Although the entanglement entropy depends upon the matter
field content of the theory, it turns out that so does the Bekenstein-Hawking
entropy $A/4\hbar G_{ren}$, in precisely the same way, because the effective
gravitational constant $G_{ren}$ is renormalized by the very same quantum
fluctuations. It appears most satisfactory if the entire gravitational action
is ``induced", in the manner suggested by Sakharov, since then the black hole
entropy is purebred entanglement entropy, rather than being hybrid with bare
gravitational entropy (whatever that might be.)
