Quality control takes place in the factory, after production but before you pay the balance. The purpose of the quality inspection is to select a sufficiently large number of samples, and check that they are made according to your specifications and quality requirements.
Factory audit takes place in the factory, as part of the supplier vetting process. The purpose of the factory audit is to assess the supplier’s production capabilities, quality management system (or lack thereof) and main products. Hence, the outcome of the factory audit may decide whether you will continue cooperation with a supplier.