  These lectures contain an introduction to the following topics: 1)
Phenomenology of the hadron spectrum; 2) The static Wilson loop in perturbative
and in lattice QCD. Confinement and the flux tube formation; 3) Non static
properties: effective field theories and relativistic corrections to the
quarkonium potential; 4) The QCD vacuum: minimal area law, Abelian projection
and dual Meissner effect, stochastic vacuum.
