Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Halloween is a celebration observed on October 31, primarily in regions of the Western world, and among those that do the traditions and importance of the celebration vary significantly. A much celebrated holiday in Ireland and Scotland, mass transatlantic Irish and Scottish immigration in the 19th century popularized Halloween in North America. The holiday is celebrated to a lesser extent in other parts of the world.Halloween is a significant cultural event in Ireland; it is widely celebrated. It is known in Irish as Oíche Shamhna, literally "Samhain Night." In the Irish language, Samhain is the name for the month of November. Pre-Christian Celts had an autumn festival, Samhain, "End of Summer," a pastoral and agricultural "fire festival" or feast, when the dead revisited the mortal world and large communal bonfires would hence be lit to ward off evil spirits