Halloween (a shortening of All Hallows' Evening), also known as Hallowe'en or All Hallows' Eve, is a yearly holiday observed around the world on October 31,
the night before All Saints' Day.
Halloween is a secular holiday combining vestiges of traditional harvest festival celebrations with customs more specific to the occasion such as costume wearing, trick-or-treating, pranksterism, and decorations based on imagery of death and the supernatural.
The word Halloween is derived from All Saints Day & Eve of All Hallows (All Hallows Eve) or Hallow Even. It was generally believed that the dead or disembodied spirits of all those who had died throughout the preceding year would come back in search of living bodies to possess for the next year. It was believed to be their only hope for the afterlife.
All who were alive of course didn't want to be possessed by these lost souls so on the night of October 31st, villagers would extinguish the fires in their homes to make them cold and inhospitable then dress up in ghoulish costumes and parade around the neighborhood making as much noise as possible to frighten away the spirits looking for a live body to possess. Food and drink would be left out for these costume wielding villages.
Typical festive Halloween activities include trick-or-treating (also known as 'Guising'), attending costume parties, carving jack-o'-lanterns, lighting bonfires, apple bobbing, visiting haunted attractions, playing pranks, telling scary stories, watching horror films, as well as the religious observances of praying, fasting and attending vigils or church services.
As one of the world's oldest holidays, Halloween is still celebrated today in several countries around the globe, but it is in North America and Canada that it maintains its highest level of popularity.