What is regression testing?

[jessie143143]

Regression testing means testing the functionality whether it is working fine when new functionality is added.

[lokeshm]

Whenever a new functionality is added or any changes are made either to the environment or to the configuration of an application, then a test is conducted to ascertain the performance of the integrated system on the whole, this test is known as Regression test.

Regression test ensures that no additional errors were introduced in the process of providing new functionality or fixing other problems.

Regression testing involves re-running affected test cases from existing test suites to ensure that the changes and modifications do not cause unexpected behaviour.

[Sandhya.Kishannag]

Regresion testing is a selective retesting of a software system that has been modified to ensure that any bugs have been fixed and that no other previously working functions have failed as a result of the reparations and that newly added features have not created problems with previous versions of the software. Also referred to as verification testing.

It is a quality control measure to ensure that the newly modified code still complies with its specified requirements and that unmodified code has not been affected by the maintenance activity.

[dheerajs]

Regresion Testing is done when some bug is fixed in a esting is done to software . This testing is done to ensure that the fixing of one issue in the application do not affect other parts or section.
In simple word it checks whether any side effect is generated or not. If the application is big we choose automation tool to do regresion testing .

[kalyansantosh]

After adding a new functionality or after fixing a bug
first we have to check the new functionality after that old functionality also why because the new functionality is effected on old functionaly or not like that we have to test that is called Regression Testing