Yasuiqian (压岁钱) means money given to children as a Chinese Lunar New Year gift which is usually put in a red envelope or paper bag (hongbao in Chinese).
Giving Hongbao during the Chinese New Year is a tradition. A red packet is simply a red envelope with gift money in it, which symbolizes luck and wealth. Red packets are typically handed out to younger generations by their parents, grandparents, relatives, close neighbors, and friends, and usually the immediate family gives Hongbao to the children on New Year's Eve. Money given in this way may not be refused and the pretty envelopes add sincerity to the gift.
The money is also called Ya Sui Qian, meaning "suppressing age money," which is supposed to stop children from getting older. This comes from the belief that everyone becomes one year older on New Year's Day. Red is the lucky color and will bring good luck to the person receiving the present.