Deconfinement phase transition in mirror of symmetries

We argue that the deconfinement phase transition in Yang–Mills theories can be viewed as a change of effective non-perturbative degrees of freedom and of symmetries of their interactions. In short, the strings in four dimensions (4d) at temperatures below the critical temperature $T_\mathrm c$ are replaced by particles, or field theories in 3d at $T>T_\mathrm c$. The picture emerges within various approaches based on dual models, lattice data and effective field theoretic models. We concentrate mostly on the lattice data, or the language of quantum geometry.