DPI, or dots per inch, refers to the measure of resolution used in printing. In the context of children's books, DPI indicates the quality and clarity of the images and text. Higher DPI values mean better image quality, making illustrations appear sharp and vivid. For instance, images intended for print typically require a DPI of at least 300 to ensure they look great on the page. Understanding DPI is crucial for authors and illustrators, as it impacts the visual appeal and professionalism of the final book.