Halloween, also known as All Hallows' Eve, is a holiday celebrated on October 31st every year. Its origin dates back to ancient Celtic festivals, particularly the Gaelic festival Samhain, which marked the end of the harvest season and the beginning of winter. It was believed that on this day, the boundary between the worlds of the living and the dead became blurred, allowing ghosts to return to earth. To ward off these spirits, people would dress up in costumes and light bonfires. Over time, Halloween has evolved into a popular holiday associated with trick-or-treating, pumpkin carving, and spooky decorations.