/tg/Station 13

I'm new to SS13 programming, and I can't understand this part of code which is taken from deck code: if(cooldown < world.time - 50) cards = shuffle(cards) playsound(src, 'sound/items/cardshuffle.ogg', 50, 1) user.visible_message("[user] shuffles the deck.", "<span class='notice'>You s...