Phase transitions can be heuristically understood as moments when physics changes its effective language. In chemistry, changes of phase are often explained as different structures of the same molecules: gas, liquid, solid. But this is a far to limited view.
A ferromagnet remains a solid across the Curie transition, but its physics changes completely. QCD and electroweak theory undergo a change of phase in a plasma where there are no atoms at all. In QCD, the language of quarks and gluons gives way to the language of protons, neutrons, and pions. In the electroweak phase transition, the Higgs field changes the language of particles and forces. In superconductivity, the language changes from ordinary electrons scattering through a metal to a collective quantum condensate
These changes in physics language are as radical as the shift from the hydrodynamic laws describign a liquid to the elastic laws of a solid