Regression Testing

Regression testing is the retesting of a software system to confirm that changes made to few parts of the codes has not any side affects on existing system functionalities. It is to ensure that old codes are still working as they were before introduction of the new change. The ideal process would be to create an extensive test suite and run it after each and every change.

ISTQB Definition : Regression testing is a type of software testing that intends to ensure that changes (enhancements or defect fixes) to the software have not adversely affected it.