Simply put, books are what we generally call books, and books and periodicals are periodicals, mostly monthly, quarterly or fortnightly.

Strictly speaking, any printed matter of more than 49 pages published by any publishing house (business), excluding the front cover and back cover, has a specific title and author's name, and is numbered with the international standard book number, priced and protected by copyright. Publications are regular or irregular publications, and generally have a fixed name and serial number.