  After a brief historical review of the emergence of QCD as the quantum field
theory of strong interactions, the basic notions of colour and gauge invariance
are introduced leading to the QCD Lagrangian. The second lecture is devoted to
perturbative QCD, from tree-level processes to higher-order corrections in
renormalized perturbation theory, including jet production in e+ e-
annihilation, hadronic tau decays and deep inelastic scattering. The final two
lectures treat various aspects of QCD beyond perturbation theory. The main
theme is effective field theories, from heavy quarks to the light quark sector
where the spontaneously broken chiral symmetry of QCD plays a crucial role.
