Pasting Spring Festival couplets originates from the Zhou Dynasty custom of hanging peach wood charms to ward off evil, which later evolved into red couplets inscribed with auspicious verses, symbolizing the welcome of blessings and good fortune. Setting off firecrackers initially involved burning bamboo to scare away the legendary "Nian" beast; after the Song Dynasty, these became gunpowder firecrackers. The loud sounds and red color both signify driving away bad luck and celebrating the new year. Together, they serve as cultural symbols of ushering out the old and welcoming the new during the Spring Festival.