What does regression testing aim to achieve?

Regression testing aims to ensure that recent changes made to the software—whether through new features, bug fixes, or other modifications—have not negatively impacted existing functionality. It is performed after changes to the codebase to confirm that previously working aspects of the application continue to operate as expected. This is essential because even minor modifications can introduce unintended side effects, and regression testing helps identify those issues early in the development cycle.

This approach is crucial for maintaining software quality over time, particularly in iterative development environments where code tends to change frequently. Regression testing not only verifies the new changes but also acts as a safety net to catch regressions—cases where fixed issues reappear or where previously functional features break due to new updates.

While other options mention aspects of testing, they do not capture the primary aim of regression testing in the context of maintaining software stability and ensuring that existing functionalities remain intact after updates are made. Thus, the focus of regression testing is specifically on the impact of changes rather than on testing new functionalities alone, documenting defect resolutions, or running tests indiscriminately without an analysis of their outcomes.