Stephen Hawking says about Black hole that it is not quite black.  Rather, it radiates energy from its event horizon. This radiate energy  is named as Hawking radiation according to the name of physcist  Stephen Hawking.   Event horizon is the boundary of black hole from where the minimum  effect of black hole exists.   Recent discovery of science is Black hole information paradox.  According to black hole information paradox, everything engulfed by  black hole is displaced and transform into information and these  information convert into energy and finally radiates through event  horizon of black hole.