Halloween is a holiday celebrated each year on October 31.
This day marked the end of summer and the harvest and the beginning of the dark, cold winter, a time of year that was often associated with human death. Celts believed that on the night before the new year, the boundary between the worlds of the living and the dead became blurred. On the night of October 31 they celebrated Samhain, when it was believed that the ghosts of the dead returned to earth.
Over time, Halloween evolved into a day of activities like trick-or-treating, carving jack-o-lanterns, festive gatherings, donning costumes and eating treats.