This understandable and inspiring book brings together both theorists and experimentalists working on the properties of nuclear and hadronic matter produced in heavy-ion collisions in various energy ranges. The main focus is on experimental signals revealing the possible phase changes of the matter.

Preface. Section I: Thermal and chemical equilibrium. Section II: Non-equilibrium dynamics. Section III: Phase transitions and the critical behaviour. Section IV: Hadronic matter and the quark-gluon plasma. Section V: Multifragmentation, liquid-gas phase transition. List of participants.