  The Beam Energy Scan (BES) program is being pursued at RHIC to study the QCD
phase diagram, and search for the possible QCD phase boundary and possible QCD
critical point. The data for Phase-I of the BES program have been collected for
Au+Au collisions at center-of-mass energies ($\sqrt{s_{NN}}$) of 7.7, 11.5,
19.6, 27, and 39 GeV. These collision energies allowed the STAR experiment to
cover a wide range of baryon chemical potential $\mu_{B}$ (100--400 MeV) in the
QCD phase diagram. We report on several interesting results from the BES
Phase-I covering the high net-baryon density region. These results shed light
on particle production mechanism and freeze-out conditions, first-order phase
transition and "turn-off" of QGP signatures, and existence of a critical point
in the phase diagram. Finally, we give an outlook for the future BES Phase-II
program and a possible fixed target program at STAR.
