What is the Difference Between Retesting and Regression Testing?

Retesting and regression testing are two important software testing techniques that serve different purposes and have distinct scopes. The main differences between them are:

• Purpose: Regression testing aims to ensure that the existing functionality of the software is not affected by recent changes, whereas re-testing aims to ensure that the specific defect that was previously found has been fixed.
• Scope: Regression testing is typically performed on the entire system or a subset of the system to ensure that the software remains stable and functional, while re-testing is performed on a specific part of the system to verify that a specific defect has been fixed.
• Timing: Regression testing is performed after any changes are made to the software, while re-testing is performed after a defect has been identified and fixed.
• Test Cases: Regression testing is performed for passed test cases, while re-testing is done only for failed test cases.
• Unexpected Side-Effects: Regression testing checks for unexpected side-effects, while re-testing makes sure that the original fault has been corrected.
• Defect Verification: Regression testing doesn't include defect verification, whereas re-testing includes defect verification.
• Automation: Regression testing can be performed with the use of automation, whereas re-testing is not possible with automation.

In summary, while both regression testing and re-testing are important aspects of software testing, they serve different purposes and have distinct scopes. Regression testing is a broader practice aimed at ensuring overall software stability, often automated, while re-testing is a focused verification of specific bug fixes, typically done manually or with fewer test cases.

Comparative Table: Retesting vs Regression Testing

Here is a table comparing the differences between retesting and regression testing:

In summary, retesting is focused on verifying that specific bugs or issues have been fixed, while regression testing ensures that overall software stability and functionality are maintained after code changes. Regression testing is a broader practice, often automated, whereas retesting is typically done manually and involves fewer test cases.