what's the meaning of elf on a shelf

The "Elf on a Shelf" tradition originated in Scandinavia and is based on the belief that mischievous elves visited homes during the Christmas season to help Santa Claus deliver presents. The elves would watch children and report back to Santa about their behavior. As part of the tradition, families would place an elf figure around their home to remind children to be good. The elf's name is "Elfie."