Saturn has seven large rings, which are named alphabetically in the order they were discovered. The main rings are A, B, and C; they are denser and contain larger particles. The fainter D, E, and G rings are also known as "dusty rings" due to the small size of their particles. The F ring — the outermost one — contains quite dense parts, but it also contains a lot of small particles, which makes it rather difficult to categorize. The rings consist of thousands of narrower ones, so the exact number is unknown.