Many books have been adapted to other media, especially movies. Movies based on books enjoy great popularity.
However, they are sometimes criticized because the characters in the movies do not look like the characters in the books.
The reason for this is that literature and film are two very different media. In literature, the reader imagines the characters and the world in which the story takes place. In film, the director and production team work to create a visual version of the characters and world of the book.
Although most movies based on books are faithful to the original story, there are bound to be some differences. These differences may be due to poor adaptation, or simply because film is a very different medium from literature.