The setting is important because the story begins on earth and enters space, allowing unique events to occur.
Setting is one of the most important elements of a fantasy or science fiction story. Because the action of the story is in a time and place so different from our own, the author can explore different themes and messages.
The story begins on a farm in our world, but then quickly goes to space when the children’s father disappears. They travel through space and time to the world of Camazotz, where their father is imprisoned, which is like ours but twisted by IT.
By making Camazotz a world like ours but deteriorated by the presence of the evil IT reminds us that we need to be cautious, and allows us to explore the theme of good versus evil.