In a lab, quality control (QC) is checking each step of an experiment to make sure it’s done correctly, while quality assurance (QA) is like a set of rules and procedures that ensure the lab operates correctly. QC involves testing equipment, materials, and results and correcting errors, while QA involves making sure everyone follows the rules, staff is trained, and regular checks are done to make sure everything is working properly. Together, QC and QA make sure that lab results are accurate and reliable.