  This paper aims at solving several open questions in current neutrino
physics: the neutrino mass hierarchy, the Dirac CP-violating phase, the
absolute mass of neutrinos, the nature of neutrinos (Dirac or Majorana), the
Majorana matrix, and the absolute value of the effective Majorana neutrino
mass. In the research presented in this paper, we have shown that the precise
definition of the mass splittings between neutrino mass eigenstates, done in
the latest analysis of experimental data, can be of crucial importance for
defining the nature of neutrino mass hierarchy. The Standard Model has three
generations of fundamental matter particles. Three generations of the charged
lepton mass show a hierarchical structure. Owing to that, there is a belief and
it is considered that neutrinos may follow such a hierarchical structure. In
our calculations, we have also included the latest data obtained, based on the
processing of measurement results, which showed that even with such data,
obtained results favor the normal neutrino mass hierarchy. As for the
individual neutrino mass calculated in this paper, in today's neutrino physics
it is only known that the neutrino mass scale is bounded only from above, and
both the Dirac and the Majorana character of neutrinos are compatible with all
observations. Among some of the questions resolved in this paper, which are
related to the properties of neutrinos, a positive answer was also given to the
question of whether light neutrinos are self-conjugate particles or not.
