Quantum ChromoDynamics (QCD) describes the interaction between the elementary constituents of hadronic matter, the quarks and gluons. Quarks and gluons are not observed as free particles, but are confined inside color-singlet hadrons. QCD, however, predicts the existence of a phase of matter at high temperature (T > 10^12 K) where quarks and gluons are no longer confined, called the Quark–Gluon Plasma (QGP). The QGP can be created and studied in the laboratory colliding heavy nuclei at ultra-relativistic energies. The ALICE experiment at the CERN LHC is pursuing this program at the energy frontier (\sqrt{s_NN} > 2.76 TeV). After a brief introduction on the physics of confinement and heavy-ion experiments, I will discuss recent results from the ALICE collaboration on the collective properties and hadronization mechanism of the system created in the collision. Moreover, recent measurements of smaller colliding systems (such as pp and p-Pb) have revealed striking similarities on observables traditionally considered to be hallmarks of heavy ion collisions. These results are currently not understood, but are leading to advancements in the description of the microscopic dynamics in high-energy hadronic interactions.