Could someone explain how the card shuffling software works?

[motorholdem]

Hi

We have all experienced folding a hand like 87hearts only to see the flop come 5,6,9, and we would have had a straight if we called. But would we??

I thought someone told me that the deck is not "static", if you will. That is, the cards are not waiting to come off the flop. Someone told me that the computer is continually cycling, and that if you fold the cards would be different than if you called, and that if you took 2 seconds to call the flop would be different than if you took 3 seconds, etc.

Is this true? If so, does this mean we never truly would have flopped whatever we see if we stayed.

Any explanation in layperson terms would be helpful.

Thx