Although it may be referred to by other names (direct exposition, objective narration, summary exposition, or simply narration), direct narration is where the narrator of the story addresses the reader directly. When conveying information by direct narration, the narrator simply states the information without any pretext of channeling it through a character or exposing it through some sort of prop.
As noted by Ansen Dibell in Plot, the simplest way is to just slip the information between scenes as the all-seeing, all-knowing (but impersonal and invisible) narrator.
But, warns Dibell, there's a price for direct narration: "Authorial intrusions-the story stopping dead while the author rambles on about whatever happens to interest him-used to be common-place, a hundred and a half years ago." For example, Melville's cetology chapters telling the folklore, anatomy, and habits of whales. "Now, though," notes Dibell, "they're much disliked."
Example of exposition through direct narration:
Meanwhile, in a saloon across the street from Cisco, Black Bart slipped a derringer into his coat pocket.
"The other choice," according to Ansen Dibell, "is to have your characters give the necessary facts . . . ."
As stated by Jordan E. Rosenfeld, "Dialogue is a wonderfully versatile technique for giving the reader information necessary to drive the plot forward or deepen character understanding . . . ."
But Dibell cautions "Don't ever put into a character's mouth anything that's strictly and obviously for the reader's consumption. Readers aren't fooled, and you've turned your characters into unconvincing puppets, dummies making silly speeches at each other."
Another way for characters to provide exposition is through thoughts, especially recollection. According to Dibell ". . . you can have the exposition as one character's reflections or thoughts-the fiction writer's version of a soliloquy. Your character can think about something . . . and thereby let the reader know what you want to convey."
Example of exposition through dialogue:
Gabby grabbed Cisco's shoulder. "Be careful, sonny. I've heard that Black Bart carries a derringer