Can someone explain me how this shit works on breeding?

"Previously, when the parent Pokémon had power items attached, it guaranteed the transfer of one of the IVs, while several IVs were guaranteed to pass down. However, as of X & Y, if you have one of the parents hold the Destiny Knot item, then 5 IVs total from either parent will be guaranteed to be transferred"

So you can only use one knot per parent?

What does it mean to have 5 IVs total transferred? It means that it transfers 5 different stats that are maxed (31 points) to the baby or does it mean that only passes 5/31 points from the maxed IV stat of the parent?

Or

Nothing of what I said makes sense so please explain to me.