Black holes are the result of the death of a giant star which collapses in on itself. This everybody knows, but where do the things entering a black hole go, these questions will be dealt with in this subtopic.
Reverse engineering the whole of creation, is the way to know about black holes. I described the creation of universe in which a dark matter particle collapses in on itself and whatever happens next you know, in a similar way the creation of black holes happen but in the place of dark matter , fundamental particles collapse into themselves creating a neutrality. The atoms collapse in on its own nucleus and in the same way as dark matter created particles, the particles start to create dark matter, or to put it differently, the fundamental subatomic particles convert into dark matter.
The dark matter is the neutral form of fundamental particles in which the electrons and other stabilizing subatomic particles are collapsed and are present as a single whole.
Many believe that black holes eat the matter and send it to another dimension. This is not true. Black holes just convert physical subatomic particles into high energy dark energy particles.
The most noticeable form of dark energy around a black hole is in the form of radiation that surrounds it, the matter which enters a black hole leaving it converted into another form of dark matter.