What is the difference between Retesting and Regression Testing?

Retesting:

• Purpose: Verify that a specific defect has been fixed
• Scope: Only the failed test case
• When: After developer fixes a bug
• Test Cases: Same test case that found the bug
• Automation: Can be automated but usually manual
• Priority: High priority
• Also Known As: Confirmation testing

Regression Testing:

• Purpose: Ensure existing functionality still works after changes
• Scope: Entire application or affected modules
• When: After any code change (fix, enhancement, new feature)
• Test Cases: All or subset of existing test cases
• Automation: Highly recommended to automate
• Priority: Can be medium to high
• Also Known As: Verification testing

Example Scenario

Bug: Login button doesn’t work with special characters in password

• Retesting: Test login with special characters again to verify the fix
• Regression Testing: Test all login scenarios (valid login, invalid login, forgot password, etc.) to ensure the fix didn’t break anything

Key Difference

Retesting = “Did we fix the bug?” Regression Testing = “Did the fix break anything else?”