  We review the properties of the strongly interacting quark-gluon plasma (QGP)
at finite temperature $T$ and baryon chemical potential $\mu_B$ as created in
heavy-ion collisions at ultrarelativistic energies. The description of the
strongly interacting (non-perturbative) QGP in equilibrium is based on the
effective propagators and couplings from the Dynamical QuasiParticle Model
(DQPM) that is matched to reproduce the equation-of-state of the partonic
system above the deconfinement temperature $T_C$ from lattice QCD. Based on a
microscopic transport description of heavy-ion collisions we discuss which
observables are sensitive to the QGP creation and its properties.
