Retesting:it is manual process in which apllication will be 
tested with entire new set of data.

DataDriven Testing(DDT)-It is a Automated testing process in
which application is tested with multiple test data.
DDT is very easy procedure than retesting because the 
tester should sit and need to give different new inputs
manually from front end and it is very tedious and boring 
prodedure.

Hi,

  Retesting means we are going to check whether the bug is 
fixed or not.

 DDT Means: while testing the Application u may want to 
check how it performs the same operation with different set 
of data..


Regards,
Satya.k

hai satya,
        absolutely your answer is wrong.
 Retesting means not checking  whether the bug is 
fixed or not.

Retesting means checking the behaviour of system for 
different sets of inputs.

One thing is important that system may behave differently 
for different i/p's.

Retesting is an manual procedure to check the system with
different i/p's

if you come for DataDriven Testing also called DDT in a 
short form is automation method for testing appilcation for 
different i/p's using winRunner or QTP tool.

Finally, In a nutshell retesting is manual process of 
testing application with different i/p's.

Data driven testing means testing the application with 
different types of inputs using a automated tool.
In DDT we supply inputs from flat files(note pad),
database,excel sheel..etc
 
if any body have doubt please mail me or you can call me

Byee friendz

your's  
Rajendra
rajendra_penumalli@yahoo.com
Ring me at:09885162742
Hyderabad

after bug is fixed we execute test case for bug is really 
fixed i.e. is retesting.

ddt means we have to execute script in a loop for 
differient input ( for functional)

hi
  suplementary to the rajendras answer
indeed retesting is test the application with different 
inputs values.but the main aim of the retesting is to check 
whether the bug is actually fixed or not.
              shafi

retesting means weather bug is fixed or not,
regression testing means to test the application one of 
objects with different data.

Retesting means: Execute the same testcases on the same 
build with different inputs.

Regression testing : Executing the same testcases on teh 
modified build to ensure the bug fixes or any side effects

DDT : is Irrespective of the Retesting or regression 
tsting, it is tested the application with differnet inputs 
on both same build or modified build.

Retesting:
After particular bug is fixed to test a particular
component. To verify the bug is fixed or not. 
Retesting is done for both purposes.
1. Making sure that the application is free of bugs after
bug fixing.
2. To find out defects in earlier stage.
So retesting is applicable before regression testing and
after regression testing and hence both testings are in
cyclic process