A literary genre is a style of writing. Your favorite literary genre might be science fiction, for example.
The word genre means "artistic category or style," and you can talk about a movie's genre, or the genre of music that drives you crazy. When you use the term literary genre, you make it clear that you're talking about books and writing. Bookstores sometimes use literary genres as a way to separate books into different sections, like "classics" or "mysteries." The word genre is French, and it means "kind, sort, or style."