To understand the internal structure of a black hole, we must understand the concept of “state of compactness” of matter, that is to say a very high level of mass/energy potential in space (GeV/cm²). This level is in the black holes and at the beginning of the universe (Big Bang). In the first case, it is a collapse of matter from gravitational fields and in the second, an expansion of space due to repulsive fields. Thus, even if the state of compactness is reached in both cases, the circumstances are not the same, nor are the related phenomena since one speaks of a gravitational centre and the other of a homogeneous and isotropic universe,… which is not the case for a black hole (homogenous) since it is oriented towards a gravitational centre. However, this state of compactness establishes itself as soon as there is an extreme collapse of matter. The quest is therefore to understand it in order to represent it and possibly calculate it. In short, what is the state of compactness of matter?