PPLNS is a way of determining how many cryptocoins you get for your shares completed. Pay Per Last N Shares is what PPLNS stands for.This method of calculating payouts includes a "luck" factor. Using PPLNS your payout per share will have a large range(30% more or less on your payouts),  but on average, PPLNS earns more than PPS (by 5% or so) in the long run (a month or more). PPS is also known as Pay Per Share. It is a more direct method where you get a standard payout rate for each share completed.This method eliminates the "luck" in your payout,  but can decrease your total income per share by around 5%.