Regression Testing

There is always a risk associated with the change introduced to an application, to reduce this risk, regression testing(RT) should be carried out during every stages of testing, after a functional change.

Today I came across a quote regarding RT...it was funny but there is a great truth in it..
"Regression testing is to keep a check that your software is not moving a step backward" ......
How true...
To sum it up, "technically",
Regression Testing is a quality control technique by which tester ensures that changes done in the application or software complies with the requirements and the introduced change doesn't inadvertently affect the other parts of the application.