Halloween is a holiday that originated from the Samhain festival, which was celebrated by the Celtic people thousands of years ago. Samhain, which means "summer's end" in Gaelic, marked the end of the harvest season and the beginning of winter. The festival was also a time when it was believed that the boundary between the living and the dead became blurred, allowing spirits to roam freely among the living. The Celts would light bonfires and wear costumes to ward off these evil spirits.
As Christianity began to spread, the Samhain festival was replaced by All Saints Day and All Souls Day, which were intended to honor saints and pray for the dead. However, the traditions of Samhain lived on in various forms throughout Europe and eventually made their way to North America through Irish immigrants. Today, Halloween is celebrated as a time for dressing up in costumes, carving pumpkins, and trick-or-treating, but its roots can be traced back to the ancient festival of Samhain.