Software Testing Tutorial18:Retesting and Regression Testing

Hello Everyone,
I have explained concept of Retesting & Regression Testing.
Retesting is Process of verify defect is fixed properly by developer team or not.
Regression testing is Process of testing whether any changed in software application has impacted on unchaged areas or not.
After every defect fixed tester can reexecute fail test case to verify whether test case is passed.
After every update in software tester perform regression on previously passed test cases.