  We review the theoretical understanding of the branching ratio and
photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD,
including consistently the effects of Fermi motion. For the Standard Model, we
obtain B(B -> Xs gamma)=(3.29 +- 0.33)*10^{-4} for the total branching ratio,
and B(B -> Xs gamma)=(2.85+0.34-0.40)*10^{-4} if a cut E_gamma > 2.1 GeV is
applied on the photon energy, as done in the recent CLEO analysis. A precise
measurement of the photon spectrum would help reducing the theoretical
uncertainty and yield important information on the momentum distribution of b
quarks inside B mesons.
