There is a saying of "open-door firecrackers" among Chinese people, namely, the first thing every Chinese household does on the New Year Day is to set off firecrackers and fireworks, illuminating the sky with strings of lights.
Fireworks and firecrackers, known as yanhua and baozhu in Chinese, were originally made of real bamboo. They were traditionally set off to frighten away ghosts and monsters so that the New Year would be free of them. Legend has it that long ago there was a monster called Nian that terrorized people and animals at the end of a year. Ancient people drove it away by the use of loud noise, bright lights and red color which the monster fears.
At midnight, on the last day of the old year, fireworks and firecrackers are used to chase away the monster Nian. You can hear or see fireworks and firecrackers everywhere, and this usually lasts for a few hours. Some people will continue to play them occasionally through out the first half of the first lunar month. Traditionally fireworks are the sign of getting rid of the old and welcoming the new. Today, fireworks and firecrackers are used to add to the merry-making of the occasion.