Can anyone tell me...?

So, in my continuing search for an agent for my novel, I’ve discovered two things: 1) this search is hard and 2) a different definition for literature.

Now, I don’t know about you, but I’ve always thought of literature as more of an umbrella term for novels, poetry, novellas, etc. Literature is writing. And, yes, I might bend that idea a bit to say that literature hints at some higher standard of novels, poetry, novellas, etc, but still.

Would someone please tell me what agencies mean when they say “we accept fiction and literature”? What’s the difference? Where’s the split? Is there a word count, or some way to measure vocabulary in a way that divides normal fiction from literary fiction? Do I have to sound like Jane Austen when I write? Because, I’ll be honest, she bores me.

Can anyone answer this for me? How do we define literature?