•Retesting is done to VERIFY defect fix previous in now working correctly where as regression is perform to check if the defect fix have not impacted other functionality that was working fine before doing changes in the code.
•Retesting is specific and is performed on the BUG which is fixed where as in regression is not be always specific to any defect fix it is performed when any bug is fixed.
•Retesting concern with executing those TEST cases that are failed earlier where as regression concern with executing test cases that was PASSED in earlier builds.
•Retesting has higher priority over regression.

•Retesting is done to verify defect fix previous in now working correctly where as regression is perform to check if the defect fix have not impacted other functionality that was working fine before doing changes in the code.
•Retesting is specific and is performed on the bug which is fixed where as in regression is not be always specific to any defect fix it is performed when any bug is fixed.
•Retesting concern with executing those test cases that are failed earlier where as regression concern with executing test cases that was passed in earlier builds.
•Retesting has higher priority over regression.