TOPOLOGICAL ASPECTS OF QCD

We review recent results from lattice on topological aspects of QCD: m ost of the results refer to monopoles and to instantons. We discuss in detail the evidence for condensation of monopoles in the vacuum and c onfinement of colour by dual superconductivity, and the major role of monopoles in dynamics (monopole dominance). As for instantons we revie w the U(1) problem, a possible determination of the spin content of th e proton, and new lattice data relevant to instanton liquid models.