If we test wehther defect is closed or not i.e Retesting
But here we r checking the impact also
regression means repeted times

Hi,

    Retesting: we are going to check weather the bug is 
fixed or not
    Regression: After getting confirmation the bug is fixed 
we are going to check the fixation is going to create any 
problems in the application or not...

Regards
Satya.K

As part of the retesting we are going to check the bug fix 
of the application is working correctly or not 

In regression Testing we are checking dependeces that means 
if the the bug fix is effecting already Existing 
functionalities or core functionalities

Retesting:is a process of testing application with 
different test data.it is done on same build.
where as regression testing is process of tesing the 
application which is already tested.it is done on different 
build

Retesting:it is done on the same build with multiple inputs 
as per the FRS to the check the validations

while

Regressing:checking the validation on the modified bulid to 
check whether the detected bug was closed or not

Regression Testing : Checking the previous error/bug has 
been rectified and no new error has been raised.

Retesting : When the major fix in a project we need to test 
from starting itself.

Regression testing :The re-execution of all test cases on a 
modified build to ensure bug fix works and occurence of any 
side effectives


Retest : The re-execution on a affected test cases