  According to the present understanding, the observed diversity of the strong
interaction phenomena is described by Quantum Chromodynamics, a gauge field
theory with only very few parameters. One of the fundamental questions in this
context is how precisely the world of mesons and nucleons is related to the
properties of the theory at high energies, where quarks and gluons are the
important degrees of freedom. The lattice formulation of QCD combined with
numerical simulations and standard perturbation theory are the tools that allow
one to address this issue at a quantitative level.
