  Extensive systematization of theoretical and experimental nuclear densities
and of optical potential strengths exctracted from heavy-ion elastic scattering
data analyses at low and intermediate energies are presented.The
energy-dependence of the nuclear potential is accounted for within a model
based on the nonlocal nature of the interaction.The systematics indicate that
the heavy-ion nuclear potential can be described in a simple global way through
a double-folding shape,which basically depends only on the density of nucleons
of the partners in the collision.The poissibility of extracting information
about the nucleon-nucleon interaction from the heavy-ion potential is
investigated.
