Phase transitions are driven and characterized by thermal, quantum or topological properties and play a central role in physics. During the Intensive Week at RPTU Kaiserslautern-Landau (Germany) concrete examples of phase transitions within the realm of ultracold quantum gases in traps or optical lattices as well as of photonic systems are treated in detail. Although all these systems are physically quite different, their respective phase transitions reveal certain similarities which will be analyzed. On the one hand, the Intensive Week aims at providing an overview over both the theoretical and the experimental probing of the respective phase transitions within pedagogical lectures of invited speakers. And on the other hand, the participants have the possibility to work out concrete examples of phase transitions in small working groups and to present their respective findings in talks. The Intensive Week is kindly supported by the Collaborative Research Center SFB/TR 185 "OSCAR": Open System Control of Atomic and Photonic Matte.