Peer-reviewed journal article vs university press book

They are similar in one important respect: both are normally evaluated by experts before publication.

The difference is mainly how the review process works.

Peer-reviewed journal article

The journal sends the article to anonymous specialists.

Those specialists write formal reports.

The editor decides whether to accept, reject, or require revisions.

The review is usually focused on one specific article.

University press book

The publisher normally sends the manuscript to expert readers.

Those readers evaluate the entire book.

The process is often less standardized than journal peer review.

The reviewers may or may not remain anonymous throughout the process.

The editor and editorial board also play a larger role.

not "peer reviewed" in exactly the journal sense and that means that university press books are usually reviewed by experts, but the process is not always identical to the formal journal-review procedure.