lol..
Thats not too hard to explain I think.
Example.
I have A7
others do a big raise (10big blinds).
I fold.
The flop comes 77A
If I say that I have a A7.
both players know now that the chances of the other having A7 is much lower since an A and a 7 is already on my hands.
Than the person who has a AA on this hand hiting a 3 of kind if aces will not be that scared of a big raise, since he know the remaning person dont have an ACE.
Got it?