I don't get what you're asking?
What it means that non-perturbative QCD is the exploration of phases of quark matter, including the quark-gluon plasma?
Because, at high energies, you're at the so called asymptotic freedom regime. At this regime, your quarks interact weakly and the perturbative calculations are possible. And quark-gluon plasma is theoretically assumed to have existed microseconds after the universe was created (because of high temperatures at the beginning of the 'Big Bang').
Also, experiments such as ALICE at the LHC in CERN and RHIC at BNL are studying the collisions that should, theoretically, produce quark-gluon plasma - a state, theoretically, where quarks and gluons are decoupled; in nature, quarks are never on their own, they are either in meson 'state' - two coupled quarks, or baryon 'state' - three coupled quarks (both part of hadrons - family of coupled quarks).
But it is still not clear how this happens, the mechanism behind it, and this is what they are seeing at the LHC indeed: Q-G plasma.
My friend worked in the ALICE experiment at CERN and he had a thesis from this field. They are studying the impulse correlations in Pb-Pb collisions and are trying to see if the Q-G plasma state emerges from these collisions using Hanbury Brown and Twiss effect. That way, from correlations of two-body wave functions, one could deduce things about hadronization of quarks - since Q-G plasma exist only for a tiny amount of time, and quarks start to hadronize very quickly, you can only see that effect, and try to see if that effect really came from Q-G plasma. But it's still not clear if the Q-G plasma was created, and they're working hard to find that out.
Oh, also you have this QCD diagram
Which describes why you need high energies to produce Q-G plasma.
I hope this clears things a bit...