Heal Tool

What exactly does the Healing Tool do? What can it be used for? And how does one use it?

 

if you mess something up.
it will try and restore it to before you messed it up

 

lets say theres a big black dot in your image and you dont want it there, with the heal tool you can select that area, and it will remove the black dot without a trace (usually)

 

Oh that? But that's why we have the control to undo mistakes o.0

 

No its not an undo. Try opening a picture of a face with a pimple on it or something. And use the heal brush on the pimple, it should take it away.