  We review the present status of the search for a phase transition and
critical point as well as anomalous transport phenomena in Quantum
Chromodynamics (QCD), with an emphasis on the Beam Energy Scan program at the
Relativistic Heavy Ion Collider at Brookhaven National Laboratory. We present
the conceptual framework and discuss the observables deemed most sensitive to a
phase transition, QCD critical point, and anomalous transport, focusing on
fluctuation and correlation measurements. Selected experimental results for
these observables together with those characterizing the global properties of
the systems created in heavy ion collisions are presented. We then discuss what
can be already learned from the currently available data about the QCD critical
point and anomalous transport as well as what additional measurements and
theoretical developments are needed in order to discover these phenomena.
