Halloween ,is also known as All Hallows’ Eve or All Saints’ Eve. It is a celebration observed in a number of countries on 31 October which is the eve of the Western Christian feast of All Hallows’ Day.
It is widely believed that many traditions originated from Celtic harvest festivals which may have pagan roots, particularly the Gaelic festival Samhain. This festival was Christianized as Halloween. Some academics however, support the view that Halloween began independently as a solely Christian holiday.
Activities include trick-or-treating, attending costume parties, decorating, carving pumpkins into jack-o’-lanterns, lighting bonfires, apple bobbing and games, playing pranks, visiting haunted attractions, telling scary stories and watching horror films. In many parts of the world, the Christian religious observances of All Hallows’ Eve, including attending church services and lighting candles on the graves of the dead, remain popular, although elsewhere it is a more commercial and secular celebration. Some Christians historically abstained from meat on All Hallows’ Eve, a tradition reflected in the eating of certain foods on this vigil day, including apples, potato pancakes and soul cakes.
Straddling the line between fall and winter, plenty and paucity, life and death, Halloween is a time of celebration and superstition.
(Source: https://en.wikipedia.org/)