The lectures collected in this book present a comprehensive review of the current knowledge of heavy-quark physics, from the points of view of both theory and experiment. Heavy Flavour Physics has accomplished enormous progress during the last few years: the last heavy quark has been discovered and the quality of the collected data on the other relatively lighter quarks has dramatically improved. On the theory side, noticeable progress has been reported on new calculations of decay rates based on various techniques, such as QCD sum rules, heavy-quark mass expansion and lattice QCD. The theory.