Omniscient Narrator in Realism
Realist writers really rocked the omniscient narrator. What's that, you ask?
Omniscient narrators are sort of like the superheroes of narrators, and that's because they know everything. They can jump from one character's head to another, they can tell us about one town on this page and then jump to a completely new town on the next. They know when you've been sleeping, they know when you're awake, they know when you've been good and bad, so… Well, yeah. They move from character to character, from scene to scene, from one place to another—because they just know it all.
Knowing it all means these narrators know the details of pretty much everything, which is a pretty convenient thing if what you're trying to do is create a sense of reality in your novel.
Of course, not all Realist literature is told from the omniscient narrator point of view—there are plenty of first-person narrators, for example, in Realist literature. But the fact is that most of the great 19th-century Realist authors wrote from an omniscient narrative point of view: Leo Tolstoy, Honoré de Balzac, George Eliot, Gustave Flaubert, Charles Dickens, to name just a few.
Chew on This
Leo Tolstoy is famous for his use of the omniscient narrator. Check out how the omniscient narrator moves between different characters in these examples from Anna Karenina.
The omniscient narrator of George Eliot's Middlemarch makes all kinds of general statements about men and women in these quotations from the novel.