  The complex system of the CMS all-silicon Tracker, with 15\,148 silicon strip
and 1440 silicon pixel modules, requires sophisticated alignment procedures. In
order to achieve an optimal track-parameter resolution, the position and
orientation of its modules need to be determined with a precision of few
micrometers. The alignment of pixels modules is crucial for the analyses
requiring a precise vertex reconstruction. The aligned geometry is based on the
analysis of several million reconstructed tracks recorded during the
commissioning of the CMS experiment, both with cosmic rays and with the first
proton-proton collisions. Statistical precision of the alignment of the module
with respect to the particle trajectories to less than 10 microns has been
achieved. The results have been validated by several data-driven studies (track
fit self-consistency, track residuals in overlapping module regions, and track
parameter resolution) and compared with predictions obtained from a detailed
detector simulation.
