In bookbinding

Bookbinding

Bookbinding is the process of physically assembling a book from a number of folded or unfolded sheets of paper or other material. It usually involves attaching covers to the resulting text-block.-Origins of the book:...

, section (sometimes gathering) refers to a group of bifolios, or sheets of paper, stacked together and folded in half. The term is sometimes used interchangeably with signature, though the latter technically refers only to the signature mark

Signature mark

A signature mark is a letter, number or combination of either or both, which is printed at the bottom of the first page, or leaf, of a signature or section...

at the bottom of the first page of a printed section.

The section is the basic building block of codex bindings. In Western bookbinding, sections are sewn through their folds, with the sewing thread linking each section to its neighboring sections.