what's the story of elf on the shelf

The story of Elf on the Shelf is a popular Christmas tradition that started in 2005 with the book "The Elf on the Shelf: A Christmas Tradition." The story follows an elf named Scout Elf who is assigned to watch over a child and report their behavior back to Santa Claus. Every night, the elf flies back to the North Pole and tells Santa what the child has done during the day. The elf then returns to the child's home and sits in a new spot each morning, waiting to be found.