All stories take place somewhere. The action needs some place to happen which is where the setting comes in. Your basic horror story always takes place in remote places because it wouldn’t work anywhere else. For example, The Shining takes place in a snowbound, closed hotel. If the hotel wasn’t snowbound, the inhabitants would have access to help. So the setting in such a story is very important. The Shining would never happen in the heart of New York City. The setting enhances the plot.
The setting can also set the mood for a story. “It was a dark, and stormy night,” invokes a mood quite different from “It was midday and sun was shining brightly.” The former produces a sense of foreboding while the latter invokes warmth and happiness.
The setting can help or hinder a character in its quest for whatever it is the character wants or needs. After all, climbing a jagged mountain peak is vastly different from walking along a level paved road. Weather conditions can hep hinder an escape. That level paved road is more dangerous when wet or in icy conditions.
Mainly though, the setting is simply a place where the action takes place. It gives the character things to do. The setting ensures that you don’t have a series of disembodied talking heads. That’s important. Consider the following dialog.
“You don’t understand me,” Tina yelled at her boyfriend. “I’m trying to tell you something important.”
“Calm down, Tina,” Ted said. “I’m listening.”
“No you aren’t!”
On the surface, the dialog is fine. We know a couple is having an argument. Look deeper. Where are they? How does Tina know Ted isn’t listening to her? Ground this scene in a setting and let’s see what’s happening.
“You don’t understand me.” Tina stood in the kitchen and yelled at her boyfriend who stood at the stove.
“Calm down, Tina.” Ted offered her a cup of coffee. “I’m listening.” He turned to flip the omelet in the pan.
“No you aren’t”
See the difference? Ted and Tina are not just talking heads. They are doing something in a kitchen. Tina believes Ted is concentrating on the eggs rather than on her words. So we have answered both our questions about the scene. The setting told us what we needed to know about the scene.
Remember to have your character interact with their setting. It prevents what I call the Talking Head Syndrome and makes the story more believable. People live the physical world. Your fictional world should reflect that. Give your characters something to do. Give them things to hold, places to go and things to do. They will be more real to the readers.
That is the ultimate goal. Pull your readers into your fictional world by making that world familiar. Let them experience it. Remember the setting has an important role to play.