In the last decade, the LEP and SLD experiments played a central role in the
study of B hadrons (hadrons containing a b quark).
New B hadrons have been observed (Bs0, \Lambda_b,\Xi_bandB^{**})andtheirproductionanddecaypropertieshavebeenmeasured.InthispaperwewillfocusonmeasurementsoftheCKMmatrixelements:|V_{cb}|,|V_{ub}|,|V_{td}|and|V_{ts}|$. We will show how all these measurements, together
with theoretical developments, have significantly improved our knowledge on the
flavour sector of the Standard Model.Comment: Talk given at the XXX SLAC Summer Institute, ssi2002, August
5-16,200