QCD vacuum and confinement
  This course consists of two lectures. In the first lecture I discuss why a non perturbative formulation of QCD is needed, and I show that lattice formulation copes with this need, even if it mainly produces numerical results. In the second lecture I discuss how lattice can help to understand the deconfinement transition.Such understanding is also important to predict parameters that can help in the interpretation of heavy ions high energy experiments. 
A. Di Giacomo