  After the discovery of the Quantum Chromodynamics (QCD), many experimental
and theoretical efforts have been made to investigate physics issues involved
in ultra relativistic heavy-ion collisions. The fundamental goal of this work
is to present a short guide of the underlying theory of strong interactions
with emphasis on the light vector mesons based on the exceptional work of
R.Rapp and J.Wambach. Today widely believed that deconfinement and chiral
symmetry restoration probably takes place in a hot and dense hadronic medium as
this produced at these collisions. We focus at the place where the examination
of the new form of matter, so-called Quark Gluon Plasma (QGP), can be done
through the investigation of the dileptonic production coming from light vector
mesons. Significant progress has been made since the last years, but still some
open questions remain at the non-perturbative mass region.
