A book review's length may vary from a single paragraph to a substantial essay.
Such a review may evaluate the book based on personal taste.
Reviewers may use the occasion of a book review for an extended essay that can be closely or loosely related to the subject of the book, or to promulgate their ideas on the topic of a fiction or non-fiction work.
Photios I of Constantinople has been called "the inventor of the book review" for his work, Bibliotheca.
[5] Newspaper reviews became prominent in the 18h century, as a form of reader responses.