Staging is a phase where changes or updates are rigorously tested in an environment that mirrors the live site, with the goal of identifying and fixing any issues or bugs. QA, on the other hand, is a broader process that covers various testing phases, including staging. QA includes activities like functional testing, regression testing, performance testing, and more to ensure the overall quality and reliability of the website. Staging is part of the QA process. It focuses on the technical aspects of testing changes before they are accepted for wider QA testing. The Duplicator plugin can be a valuable tool for creating stable and secure staging environments, contributing to a great QA process.