Signals of Deconfinement Transition in Nucleus-Nucleus Collisions

We discuss the energy dependence of hadron production in relativistic nucleus-nucleus collisions. Several `anomalies’ in the energy dependence have been predicted as signals of the deconfinement phase transition and three of these signals are observed at the CERN SPS indicating that the onset of deconfinement in Pb+Pb collisions is located at about 30 A GeV.