Answer:
1. Samhain
2. All Hallows Eve
3. The tradition originated with the Celtic festival of Samhain, where people would light bonfires and wear costumes to ward off ghosts and spirits.
4. Reminders of death and were also used to ward off the ghostly presence of Stingy Jack who wandered the earth once a year.
5. Originated in Scotland and Ireland, from the tradition of guising. Children would go house to house at Halloween and put on a small performance to be rewarded with food or treats.