Halloween has its origins in the ancient Celtic festival of Samhain, marking the end of the harvest season and the beginning of winter. Traditionally, Celts believed that on Samhain, the boundary between the living and the dead became blurred, allowing spirits to return to Earth. The holiday was Christianized as All Hallows' Eve by the Catholic Church in the 7th century to coincide with All Saints' Day. Over time, traditions such as wearing costumes and carving jack-o'-lanterns developed, and the holiday spread to North America in the 19th century with Irish and Scottish immigrants. Today, Halloween is celebrated commercially with costumes, decorations, and children's activities like trick-or-tre