Waits - Difference of PolledWait, TriggerSleep, etc.

I think I'm pretty experienced to jass now but I still have this question, whats the great difference of TriggerSleep() and PolledWait()? And there was a function to break the minimum time, what one was that? Just forgot^^

TriggerSleepAction is the normal sleep, it waits for a certain amount of time, but not less than about 0.25 . It is also pretty inaccurate.
PolledWait uses TriggerSleepAction to sleep, but it also uses a timer to make the sleep more accurate by checking several times (polling) what the remaining time to sleep is and then goes there by small sleeps.

To get below the minimum, use a timer and then the handler func parameter of that timer.

So you mean I should better use the PolledWait actions in my jass enhanced spells?
Sorry but my english isn't the best

If you want accuracy, best use a timer.