n ages 7–9. Longer chapter books, appropriate for children ages 9–12. Young-adult fiction, appropriate for childre

The criteria for these divisions are vague, and books near a borderline may be classified either way. Books for younger children tend to be written in simple language, use large print, and have many illustrations. Books for older children use increasingly complex language, normal print, and fewer (if any) illustrations. The categories with an age range are listed below:
Picture books, appropriate for pre-readers or children ages 0–5.
Early reader books, appropriate for children ages 5–7. These books are often designed to help a child build his or her reading skills.
Chapter book, appropriate for children ages 7–12.
Short chapter books, appropriate for children ages 7–9.
Longer chapter books, appropriate for children ages 9–12.
Young-adult fiction, appropriate for children ages 12–18.
Illustration[edit]

Pictures have always accompanied children's stories.[8]:320 A papyrus from Byzantine Egypt, shows illustrations accompanied by the story of Hercules' labors.[39] Modern children's books are illustrated in a way that is rarely seen in adult literature, except in graphic novels. Generally, artwork plays a greater role in books intended for younger readers (especially pre-literate children). Children's picture books often serve as an accessible source of high quality art for young children. Even after children learn to read well enough to enjoy a story without illustrations, they continue to appreciate the occasional drawings found in chapter books.


A late 18th-century reprint of Orbis Pictus by Comenius, the first children's picture book.
According to Joyce Whalley in The International Companion Encyclopedia of Children's Literature, "an illustrated book differs from a book with illustrations in that a good illustrated book is one where the pictures enhance or add depth to the text."[1]:221 Using this definition, the first illustrated children's book is considered to be Orbis Pictus which was published in 1658 by the Moravian author Comenius. Acting as a kind of encyclopedia,Orbis Pictus had a picture on every page, followed by the name of the object in Latin and German. It was translated into English in 1659 and was used in homes and schools around Europe and Great Britain for years.[1]:220
Early children's books, such as Orbis Pictus, were illustrated by woodcut, and many times the same image was repeated in a number of books regardless of how appropriate the illustration was for the story.[8]:322 Newer processes, including copper and steel engraving were first used in the 1830s. One of the first uses of Chromolithography (a way of making multi-colored prints) in a children's b