Regression testing is nothing but execution of existing test
cases on the new build.

This is a black box testing, here we are going to ensure 
the wether code changes cause any change in the existing 
functionality

Regression Testing is Testing the software weather The bug 
fixed is working without affecting previously tested 
functionality

Regression testing as the name suggests is used to test / 
check the effect of changes made in the code.

Regression Testing is retesting unchanged segments of 
application. It involves rerunning tests that have been 
previously executed to ensure that the same results can be 
achieved currently as were achieved when the segment was 
last tested.

The 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 fixes and that newly added features have not 
created problems with previous versions of the software.

More on Regresison testing:
http://quality-assurance-software-
testing.blogspot.com/2005/09/regression-testing.html

Regression testing is testing of application after fixes or 
modification of software or its environment. In regression 
testing you have to check present changes should not make 
any problem with other data

retesting the previously tested applications to make sure
that changes are not cause any side effects.
 it is conducted on modified build

REexecution of Subset or all test that havebeen conducted 
earlier to determine the resolved bug has nade any imapct 
on the remaining part of the code

Regression testing is a type of testing done on modified 
build  to ensure that the the defect is solved and it has 
no side effects on other functionality.

Regression is a  Testing to test that the
Fixes/Modifications have not create anyother problems else
where in the Software.

Regression Testing:

Whenever tester find any defect it will given for developer 
for correction. After developer correct the defect it once 
again go to tester.The tester now do the testing from the 
begining to ensure that cases are without any defect and 
particular defect has been corrected.This procees of 
testing called regression testing.

Regression Testing:

   After geting confirmation the bug is fixed we are going 
to check the fixation is going to create any problems in 
the application or not.

Selective re-testing of a system to verify the modification
(bug fixes) have not caused unintended effects and that 
system still complies with its specified requriements.

Regression Testing is nothing but reverification of the 
application.It is done on modified build.In this Testing,
tester First tests defect detected modules. After that 
tester tests remaining  modules. If tester got any defect 
in that modules he again send error report to developers.
There is no end for Regression Testing.

Regression Testing: Testing any previousely not tested 
module is called regreesion testing!

Regression testing is a type of testing in which one will 
perform testing on the already tested funcanality once 
again, to make sure that when ever new changes are made by 
the development team all the related functions are working 
fine as previous.

What is regression testing is the type of testing that
ensures the software remains intact. A baseline sets of data
and scripts are maintained and executed to verify that
changes introduced during the release have not "undone" any
previous code. Then expected results from the baseline are
compared to results of the software under test. All
discrepancies have to be highlighted and accounted for,
before the testing proceeds to the next level.

The Test Engineer is Reececuting previously failed test on
modified s/w build to ensure the correctness of defect
solving and reexecute previosuly related passed test on that
modified build to defect side effects.

The Test Engineers are reexecuting previously failed test on
same s/w build after solving environment related (or) test
case related/ Test data related defects. after solving code
related defect only the test engineers are receiving
modified s/w build with release note.

regression testing to test the build once the developers
release the build to test the total core functionality is
called regression testing

Regression Testing: which Test a SYSTEM once again to 
ensure that functions as still expected as per the 
specifications or its requirements.
or 

executing the test cases on modified form of build.

Regression testing:
 
If a bug occurs in one module and send that bug to a developer
then developer fix the bug and again send to tester .Then the  
tester must check not only the bug related module he must
check the entire whole application ( i mean remaining all
the modules) after the bug is fixed.

Regression Testing:

it is defined as the type of testing in which an already
tested functionality is once again tested whnever thr is a
change i.e., associated with it in order to check whether
the existing functionality has got effected or not....