A book review is an article that may do any combination of the following:
Reviews might be written by journalists or other professional reviewers, or sometimes by authors of other books. While scholars review books in scholarly journals, these articles are normally much more brief than research articles, literary analysis or scholarship. When you are looking for reviews, you are generally trying to find out what people thought of a book at the time it was originally published, rather than finding extended analysis of a book's themes or ideas. In some cases reviews may be quite long and in-depth, as in the New York Review of Books, but this is the exception rather than the rule.
A book review should not be confused with a scientific review article or a literature review, both of which summarize previous research on a particular topic.