A best-selling novel is a book that has sold a significant number of copies, often ranking high on sales charts. These novels can span various genres, including fiction, non-fiction, mystery, and romance. The popularity of a best-selling novel can be influenced by factors such as marketing, author reputation, and cultural trends. Best-selling novels are often featured on lists like the New York Times Best Sellers or Amazon's Best Sellers. They may also receive adaptations into other media, such as films or television series, further increasing their visibility and sales.