Regression testing:

Testing the application after changes in a modular part of 
an application for testing that is the code change will 
affect rest of the application.

Retesting :

Retesting meance we testing only certain part of an 
application again and not considering how it will effect in 
other part or in the whole application

regression: Testing the already tested funcionality once
again that is known as regressin testing..
retesting: testing the same functionality onceagain with
multiple sets of data is known as retesting..

Regression testing -regression testing is nothing but 
retesting  software to detect faults introdued during the 
modification .Like it verifies whether new bugs have been 
introdued after after fixing prevoulsly idetified 
bugs,without regression testing any changes introduced to 
the code would go undetected.

Retesting: testing the functionality Number of times 
whether its working according to BRS OR FRS.

Re-testing : it means testing a particular modified build or
application with multiple sets of data or by giving
different inputs,whether the bug is fixed or not..

after conformation, that the bug is fixed...we do

regression Testing : it means , testing the modified module
or application whether the application will show impact on
other application or not...!

IF UR NOT CLEAR....THEN GO ON VTH THIS BELOW LINK.. 

http://www.allinterview.com/showanswers/58585.html

PRIYAN
priyanonlyone@gmail.com