  A particle flow event-reconstruction algorithm has been successfully deployed
in the CMS experiment and is nowadays used by most of the analyses. It aims at
identifying and reconstructing individually each particle arising from the LHC
proton-proton collision, by combining the information from all the
subdetectors. The resulting particle-flow event reconstruction leads to an
improved performance for the reconstruction of jets and MET, and for the
identification of electrons, muons, and taus. The algorithm and its performance
will be described. The commissioning phase, during which it was demonstrated
that the algorithm was performing as expected from the simulation up to a high
level of precision, will be presented. Finally, a selection of recent
improvements in the CMS analyses obtained thanks to the particle-flow algorithm
will be discussed.
