Flavour Physics: the questions, the clues and the challenges

Flavour physics addresses some of the questions for which the Standard Model does not provide a satisfactory and complete answer: the origin of the replication of the fundamental constituents and of their mass hierarchy. This paper reviews some of the theoretical approaches and the experimental strategies that can lead us to a more complete picture. Results included in this review are |V_{cb}|= 0.0382 +/- 0.0032, |V_{ub}/V_{cb}|=0.085 +/- 0.023 and a preliminary measurement of the branching fraction of B -> pi^+ pi ^- = (0.47 ({+0.18}-{-0.15}) +/- 0.06) x 10^{-5}.}