Halloween has its origins in the ancient Celtic festival of Samhain. Celts believed that on October 31, the boundary between the living and dead became blurred, allowing spirits to pass through. People would wear costumes and masks to imitate evil spirits or appease them. Modern Halloween traditions evolved from Celtic harvest festivals and Christian holidays. Children now go door-to-door seeking treats, wearing costumes of monsters, ghosts, and other supernatural figures to commemorate the dead. Carving pumpkins and exchanging candy have become synonymous with the annual Halloween celebration on October 31st.