Images can be used in many types of books.
When I wrote the text, I mainly had autobiographies in mind, but pictures can be used for many kinds of books.
In children’s books, pictures are often a supporting element, especially in textbooks. In some children’s books, photos are used, but illustrations are often used. Gift books or coffee table books are the equivalent of the adult world to the textbooks to the extent that the photos and the book’s design can be as important as the text (sometimes more important).
In many non-fiction books, illustrations are important for explaining, conveying and supporting the book’s content. This applies to everything from tables to drawings of flowers in a flora. In travel literature, especially travel guides, inspiring pictures and show what is there to see on the site.
Most fiction books are published without pictures, but some bestsellers are published in illustrated special editions. In memoirs, images can give both the reader’s authenticity and recognition.
In some books, images are as important as the text and the illustrator or photographer’s name is on the front of the book, the same size as the author. In other books, they are an optional supplement.
The advantages of including images in, for example, an autobiography are that it increases the book’s value to the reader, which means that you can charge a higher price if you want to sell it. Pictures also fill in if you are unable to write so much text but still want the book’s proper size.
The disadvantage of pictures is that it is more expensive and more complicated to publish the book. Most people who are familiar with their word processing program can write and design a textbook to keep the printable quality. The same does not apply to books with pictures in.