Halloween, also known as All Hallows' Eve, is a holiday celebrated annually on October 31st. The holiday has its roots in the ancient Celtic festival of Samhain, which was celebrated on the same day. Samhain marked the end of the harvest season and the beginning of winter, a time of year when it was believed that the boundary between the worlds of the living and the dead became blurred.

During Samhain, the Celts would light bonfires and wear costumes to ward off evil spirits. They also believed that on this night, the spirits of their ancestors would return to visit them. When the Roman Empire conquered the Celtic lands, they merged their own festivals with Samhain, and over time, the holiday evolved into what we know today as Halloween.

In the United States and Canada, Halloween is celebrated with costumes, trick-or-treating, and pumpkin carving. It has become a major cultural phenomenon, with millions of people participating in the festivities each year. While the holiday has its roots in ancient traditions, Halloween has evolved into a fun and exciting holiday for people of all ages.