Difference Between Regression and Retesting

 

                                    Difference Between Regression and Retesting

Regression	Retesting
Regression Testing is performed to make sure the code changes have not affected existing features.	Re-testing is performed to make sure that the test cases which failed earlier are passed after the defects are fixed.
Regression testing is carried out to verify whether there is any existing features are affected or not on the basis of new code changes.	Re-testing is carried out on the basis of the Defect fixes.
Defect verification won’t fall under regression testing.	Defect verification falls under retesting.
Priority of regression testing is lower than retesting. Regression testing is carried out in parallel with retesting.	Priority of retesting is higher than regression testing. Retesting is carried out before Regression testing.
We can automate regression test cases. Manual regression testing is more expensive and time consuming.	We cannot automate the test cases for Retesting due to uncertainty.
We do regression testing on passed test cases.	We do retesting only on failed test cases.
Regression test cases are derived from the functional specification.	Test cases that are failed earlier are used in retesting.
Regression testing verifies unexpected side effects.	Re-testing verifies whether original defects has been fixed or not.
Regression testing can be done in parallel with retesting.	Retesting is of high priority so it’s done before the regression testing.
For regression testing test cases can be automated.	For retesting the test cases cannot be automated.
Test cases of regression testing can be obtained from the specification documents and bug reports.	Test cases of retesting can be obtained only when the testing starts.