  The general scheme for the treatment of relaxation processes and temporal
autocorrelations of dynamical variables for many particle systems is presented
in framework of the recurrence relations approach. The time autocorrelation
functions and/or their spectral characteristics, which are measurable
experimentally (for example, due to spectroscopy techniques) and accessible
from particle dynamics simulations, can be found by means of this approach, the
main idea of which is the estimation of the so-called frequency parameters.
Model cases with the exact and approximative solutions are given and discussed.
