Question, is digital cleanup needed? What does it do?

[peterpijpelink]

In a software program called Thumbsplus which I use there is an option called: "Digital camera cleanup" and an option "cleanup jpeg".

When I use them sure some colors and such are changing, question is if I have to do this to all my pictures...

Anyone have an idea what it exactly does? I asume remove noise is one part, but that is all what I can think of so far.

thanks