In movies, we see a visual of the story world which includes a complex and detailed web of elements that have story meaning. We create the story world with infinite detail, for it is the manifestation of the character that the story brings forth in its narrative. The story world comprises of the land (natural setting), the people (man-made spaces), technology (tools), and time (changes caused through the story time). For example, in the movie "Harry Potter and the Sorcerer's Stone," the story world comprises of a school for wizards in a giant magical castle. The story begins in the mundane world and moves into this fantasy world of the Hogwarts School. The story plays out over the course of the school year in a large but defined place with seemingly infinite subworlds.
The story world reflects the people who inhabit it. When used skillfully, the story world can impact your story plot, develop characters, or even reveal the story theme. An engaging and realistic story world is one of the most important hooks you can establish. Supplying the audience with familiar reference points engages them emotionally with sights, sounds, tastes, and feelings. In the Harry Potter movie, the Hogwarts School is a modern day prep school set in a medieval world of castles, lakes and forests. The technology is another hybrid: magic with a high-tech flavor to it, where the latest witch's broom is the Nimbus 2000 and the techniques of magic are taught with all the depth and rigor of a modern-day university. The school itself is the ultimate warm house, with several nooks and crannies filled with a community of students and teachers. The center of the warm house is the great dining hall, the cathedral-like space hung with banners that hark back to King Arthur and the days of chivalry.
In a fantasy, science fiction, or historical epic, the storytelling will need much more visual picture than the familiar. Research is imperative, of course, but more than half of it may never be used. Researching the story world provides all kinds of fodder for creativity. Knowing the large amount of detail helps craft the story from the best perspective. But the audience may not be fascinated with the exact measurements of the Nimbus 2000, unless it is critical for Harry Potter to take flight on it as part of the narrative.
Taking photographs of buildings and streets in a certain neighborhood that catches your eye while traveling, can become visual inspiration. Picture books and Time Life photographs can become excellent resources for creating the realistic story world you might be seeking. The importance of such details lie in how the story world affects the characters, how it compels them, how it makes them feel, and how they react to it. Our whole focus during storytelling is to make our audience care. If the characters in the story care about the details of the story world, the audience will care about them as well.