  We discuss the most important Physics thus far extracted from studies of B
meson decays. Measurements of the four CP violating angles accessible in B
decay are reviewed as well as direct CP violation. A detailed discussion of the
measurements of the CKM elements V_{cb} and V_{ub} from semileptonic decays is
given, and the differences between resulting values using inclusive decays
versus exclusive decays is discussed. Measurements of "rare" decays are also
reviewed. We point out where CP violating and rare decays could lead to
observations of physics beyond that of the Standard Model in future
experiments. If such physics is found by directly observation of new particles,
e.g. in LHC experiments, B decays can play a decisive role in interpreting the
nature of these particles.
