  This review paper provides a summary of the published results of the Sudbury
Neutrino Observatory (SNO) experiment that was carried out by an international
scientific collaboration with data collected during the period from 1999 to
2006. By using heavy water as a detection medium, the SNO experiment
demonstrated clearly that solar electron neutrinos from $^8$B decay in the
solar core change into other active neutrino flavors in transit to Earth. The
reaction on deuterium that has equal sensitivity to all active neutrino flavors
also provides a very accurate measure of the initial solar flux for comparison
with solar models. This review summarizes the results from three phases of
solar neutrino detection as well as other physics results obtained from
analyses of the SNO data.
