Semileptonic decays and $\mathrm{\mid }{V}_{xb}\mathrm{\mid }$ determinations

We briefly summarize up-to-date results on the determination of the parameters of the Cabibbo-Kobayashi-Maskawa matrix $\mathrm{\mid }{V}_{cb}\mathrm{\mid }$ and $\mathrm{\mid }{V}_{ub}\mathrm{\mid }$, which play an important role in the unitarity triangle and in testing the Standard Model, and recent results on semileptonic $B$ meson decays involving a $\tau$ lepton.