  This is a short write-up of lectures at UK Theory Institute, Swansea UK,
Sept.99; and XVII School ``QCD: Perturbative or Non-perturbative?''
Lisbon,Portugal, Oct.99. The covered topic include (i) discussion of the scales
at which perturbative description should be changed by the non-perturbative
one. A number of various examples are considered, leading to different scales,
related to instantons or confinement effects; (ii) Instanton vacuum as an
Instanton Liquid; (iii) The phase diagram of QCD at finite temperature and
density, and especially description of a recent progress in Color
Superconductivity.
