Or 端午节 (duānwjié) is a holiday celebrating the life(or death) of ancient chinese poet 屈原Qū Yuán who lived during the warring states period. He spoke out against his native Chu state when it formed and an alliance with the Qin state. As a result he was banished to exile. Many years later Qin ended up invading and conquering the Chu state. Qu really took it hard and committed suicide by drowning himself in a local river. The local people who admired Qu Yuan threw rice balls into the river for the fish to eat instead of feasting on Qu Yuan’s corpse.
Im not sure how that transferred into racing dragon boats but the second tradition making and eating 粽子（zòng zi）pictured above and below kind of tie in to part of the story with the rice balls. To make 粽子 you take glutinous rice,wrap it in a bamboo leaves then tie it up with string and boil it. There are two variations of 粽子 one 甜(tián)sweet and the other 咸(xián) salty. the 甜(tián)sweet (my personal favorite) has red bean inside and the 咸(xián) salty usually has some kind of meat. There are probably plenty of celebrations going on this coming weekend in your local chinatown area so check it out. The vendors will probably be selling some 粽子（zòng zi）too, some will even let you try and make your own.
Not bad for a 老外 eh？