  An efficient and precise reconstruction of charged-particle tracks is crucial
for the overall performance of the CMS experiment. During Run 2 of LHC,
significant upgrades were made to the track reconstruction algorithms in order
to accommodate for the high pileup environment and the installation of an
upgraded pixel detector in 2017. This paper provides an overview of the
iterative track reconstruction algorithm used in CMS during Run 2 and of the
performance measured both with simulated and collision data. Developments are
ongoing to further improve track reconstruction in Run 3, especially for what
concerns the CMS high-level trigger, and the status of these improvements will
be discussed.
