Required by law, most public companies must periodically (at least every three years) provide their shareholders with an advisory vote on the compensation of the most highly compensated executives. Companies are required to disclose (usually in a proxy statement) how their compensation policies and decisions have taken into account the results of their most recent say-on-pay vote.
Source: http://investor.gov/glossary/glossary_terms/say-pay-vote#.Us7wGmRDuEg