Regression testing is nothing but executing the same test
cases on the different build.
  it will be needed when an bug was fixed or when a new
functionality is added to existing functionality..

re execution of test cases on the modified build to 
determine whether the defects are closed or not

regression testing is testing the newmodules without 
affecting the existing modules

Hi Naresh, you are correct. But here we dont execute all 
the test cases. We execute only the effected module test 
cases or effected functionality.

It might be full dependent on the time.

If we have no time we will check only the issue(sometimes).

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 reparations and that newly added features 
have not created problems with previous versions of the 
software

Hi,

Regression testing means after getting confirmation the bug 
is fixed we going to check the fixation is going to create 
any problems in the application or not..

   It should be required if there are any change requests.
and if the number of bugs that are found the tester are 
high...

I agree with Satya to some extend. To my view Regression 
Testing is the process of retesting the application after a 
defect is fixed, to check if due to this fixed, no other 
problems is caused to its related features. 
     Lets take an example: 
           In our application, there are 10 features,
Ft1
Ft2
Ft3
Ft4
Ft5
Ft6
Ft7
Ft8
Ft9
Ft10
 Lets consider, defects are fixed in Ft4 and Ft8. Now, to 
run the regression, we have to check which features are 
inter-related to the features Ft4 and Ft8, say Ft3 & Ft5 
for Ft4 and Ft7 & Ft9 for Ft8. Once its identified, the 
related testcase are identified from Ft3, Ft5, Ft7 and Ft9. 
And these related testcases are used for running the 
Regression.

Regression Testing run whenever changes are made in the 
Application.

Hi ,

  I think, We will go for regression testing whenever a new 
functionality is added to the application and it should not 
affect the existing one.

Regression testing means test the application fix the Bug
not effected do to the other module.

regression testing is needed whenever new modules are added 
to an existing old one.To check the functionalities whether 
the addition of new one affects the functionality of the 
old.

regression testing is nothing but testing the existing 
system.it needed at the time of updating to the system.

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

regression testing is done when new functionality added to 
the existing funcionality.

Its kind if testing which will conduct on bugs fixed build
to identified whether any side effects introduced as well as
to improve the confidence level of bug fixing

When we are at the moment of release a software build into
the market with out any defects then to get the confidence
of bug free product we need to conduct regression testing on
the overall project.