Quality assurance (QA) and quality control (QC) are both important processes in ensuring that a product or service meets the desired level of quality, but they differ in their focus and objectives.

QA is a proactive process that aims to prevent defects by establishing and enforcing standards and procedures throughout the product or service development lifecycle.

QC is a reactive process that aims to identify and correct defects after they have occurred, typically through inspection and testing of the final product or service.

In summary, QA is concerned with preventing quality issues from happening in the first place, while QC is concerned with detecting and correcting quality issues after they have occurred.