Regression Testing V/s Retesting

Regression Testing	Re Testing
Testing the unchanged functionalities of application to make sure it is not broken because of changes.	Verifying whether the bug is fixed or not
Defect verification is not the part of Regression Testing	Defect verification is the part of re-testing
Based on the project and availability of resources, Regression Testing can be carried out parallel with Re-testing	Priority of re-testing is higher than regression testing, so it is carried out before regression testing
You can do automation for regression testing, Manual Testing could be expensive and time-consuming	You cannot automate the test cases for Retesting
Regression testing is done for passed test cases	Retesting is done only for failed test cases
Regression testing checks for unexpected side-effects	Re-testing makes sure that the original fault has been corrected
Test cases for regression testing can be obtained from the functional specification, user tutorials and manuals, and defect reports in regards to corrected problems	Test cases for retesting cannot be obtained before start testing.