Who cares how your future novel is classified? You do if I tell you that your book is more easy to peddle if it falls into a clean category. Now that's been put upfront, write what ever you feel like. Be that as it may, Wikipedia is a good starting point. Here's a good link. https://en.wikipedia.org/wiki/List_of_writing_genres#Literary_fiction_vs._genre_fiction
If you query an agent saying that you've written a bestseller, work of art, a unique book, or An Outstanding Work of Staggering Genius , you will probably get you a polite form letter saying that the agent is not interested. (The Outstanding Work was just a memoir, but a superb literary, sad, and humorous book). Agents, publishers, booksellers, readers all want to know what kind of novel they'll be looking at. Most any category of novel can be a best seller.
Some people divide the whole world of fiction into genre and literary categories. These two broad categories are difficult to define (the Wiki link above contains a rather bad definition). Here's my attempt. Literary fiction is often described as more about characters and genre fiction more about plot. There are many exceptions to this statement. Lots of fine books, including some best sellers (Little Fires Everywhere) have both memorable story lines and characters (Moby Dick). The Wikipedia link above gives dozens of subcategories, more particularly for genre fiction, but also for literary fiction. Maybe the best definition is that if it's easy to categorize, it's more likely to be genre fiction. Then there are the terms, "commercial, crossover, upscale commercial, upmarket". Here's an elegant website that takes a deeper dive into these categories with some good examples (some of which I also disagree with). https://therookiewriter.net/episode-010-commercial-vs-upmarket-vs-literary/ How's that for me ducking definitions?
By now you may be wondering what kind of novels I've been writing. They've been called medical fiction, medical thrillers, mainstream, and upscale commercial. So I'm as confused as you are. What my novels are about will come later, when you have decided what your novel is about. Think logline.
