Bunkoban

A tankōbon (単行本^?, "independent/standalone book") is the Japanese term for a book that is complete in itself and is not part of a series or corpus. In modern Japan, though, it is most often used in reference to individual volumes of a single manga, as opposed to magazines (雑誌, zasshi^?), which feature multiple series. Tankōbon are not just confined to manga, and can be used for almost anything in a hardcover or softcover format from novels to books about beauty tips.

Typically, manga are first published in thick, phone-book-sized weekly or monthly anthology manga magazines (such as Afternoon, Weekly Shōnen Jump, or Hana to Yume). These anthologies often have hundreds of pages and dozens of individual series by multiple authors. They are printed on very cheap newsprint and are considered disposable. A tankōbon collects multiple installments from a single series and reprints them in a roughly paperback-sized volume on higher quality paper than in the original magazine printing. However, any colored images from the magazine publication are typically grayscaled.

In English, while a tankōbon translation is usually marketed as a "graphic novel" or "trade paperback", the transliterated terms tankoubon and tankōbon are sometimes used amongst online communities. Japanese people frequently refer to manga tankōbon as komikkusu (コミックス), from the English word "comics". The term also refers to the format itself—a comic collection in a trade paperback sized (roughly 13 × 18 cm, or 5" × 7") book (as opposed to the larger 18 × 25 cm / 7" × 10" format used by traditional American graphic novels). Although Japanese manga tankobon may be in various sizes, the most common are Japanese B6 (12.8 × 18.2 cm, 5.04" × 7.17") and ISO A5 (14.8 × 21.0 cm, 5.83" × 8.2"). The tankōbon format has made inroads in the American comics market, with several major publishers opting to release some of their titles in this smaller format, which is sometimes also called "digest format" or "digest size". In America, many manga are released in the so-called "Tokyopop trim" or "Tokyopop size" (approximately 5" × 7.5"), originally introduced by Tokyopop as a compromise between the aspect ratios of the A5 and JB6 sizes.

...
Wikipedia