Why the Entropy of a Black Hole is $A\mathrm{/}4$?

A black hole considered as a part of a thermodynamical system possesses the Bekenstein-Hawking entropy $S_H=A_H\mathrm{/}(4l_P^2)$, where $A_H$ is the area of a black hole surface and $l_P$ is the Planck length. Recent attempts to connect this entropy with dynamical degrees of freedom of a black hole generically did not provide the universal mechanism which allows one to obtain this exact value. We discuss the relation between the ‘dynamical’ contribution to the entropy and $S_H$, and show that the universality of $S_H$ is restored if one takes into account that the parameters of the internal dynamical degrees of freedom as well as their number depends on the black hole temperature.