Explanation:
- The purpose of regression testing is to confirm that a recent program or code change has not adversely affected existing features.
- Regression testing is nothing but a full or partial selection of already executed test cases that are re-executed to ensure existing functionalities work fine.
- This testing is done to make sure that new code changes should not have side effects on the existing functionalities. It ensures that the old code still works once the new code changes are done.
The purpose of regression testing is to select test cases partially or fully to ensure existing functionalities work fine. Thus, regression testing is primarily related to functional testing
Need of Regression Testing
- Regression Testing is required when there is a change in requirements and code is modified according to the requirement or when one of the following has been done.
- New feature is added to the software
- Defect fixing
- Performance issue fix


