  The lectures, delivered at ECT (European Centre for Theoretical Studies in
Nuclear Physics and Related Areas) in Trento (Italy) in 2002 and 2003, are
addressed to physicists who wish to acquire a minimal background to understand
present day attempts to model the confinement of quantum chromo-dynamics (QCD)
in terms of dual superconductors. The lectures focus more on the models than on
attempts to derive them from QCD. They discuss the Dirac theory of magnetic
monopoles, the world sheet swept out by Dirac strings, deformations of Dirac
strings and charge quantization, gauge fields associated to the field tensor
and to the dual field tensor, the Landau-Ginzburg (Abelian Higgs) model of a
dual superconductor, the flux tube joining two equal and opposite
color-electric charges, the Abrikosov-Nielsen-Olesen vortex, the divergencies
of the London limit, the comparison of the calculated flux tube and string
tension with lattice data, duality transformations and the use of Kalb-Ramond
fields, the two-potential Zwanziger formalism, abelian gauge fixing and abelian
projection, the occurence of monopoles in an abelian gauge, the maximal abelian
gauge, and the confinement of static SU(3) color charges.
