What is the purpose of a regression test case?

The purpose of a regression test case is to ensure that new changes do not negatively affect existing functionality. When software undergoes updates, whether it's the addition of new features, bug fixes, or enhancements, it's crucial to confirm that these changes haven’t introduced any new bugs or compromised the functionality of features that were previously working correctly. Regression testing involves re-running a set of tests that cover the existing features to verify their continued performance and reliability after the changes have been made.

This type of testing helps maintain quality in the software development lifecycle by catching any unintended consequences of modifications early in the process, thus preventing potential issues in the production environment. It is not solely focused on new features, performance evaluation, or user feedback, making it distinct from those other aspects of software testing.