  In different approaches, the temperature-baryon density plane of QCD matter
is studied for deconfinement and chemical freezeout boundaries. Results from
various heavy-ion experiments are compared with the recent lattice simulations,
the effective QCD-like Polyakov linear-sigma model, and the equilibrium thermal
models. Along the entire freezeout boundary, there is an excellent agreement
between the thermal model calculations and the experiments. Also, the thermal
model calculations agree well with the estimations deduced from the Polyakov
linear-sigma model (PLSM). At low baryonic density or high energies, both
deconfinement and chemical freezeout boundaries are likely coincident and
therefore the agreement with the lattice simulations becomes excellent as well,
while at large baryonic density, the two boundaries become distinguishable
forming a phase where hadrons and quark-gluon plasma likely coexist.
