Preface; 1. Introduction; 2. Path integral and lattice regularisation; 3. O(n) models; 4. Gauge field on the lattice; 5. U(1) and SU(n) gauge theory; 6. Fermions on the lattice; 7. Low mass hadrons in QCD; 8. Chiral symmetry; Appendix 1. SU(n); Appendix 2. Temporal gauge quantization in the continuum; Appendix 3. Fermionic coherent states; Appendix 4. Spinor fields.