Definition & Meaning of "bifolium"

What is a "bifolium"?

A bifolium is a sheet of paper or parchment that is folded in half to create four pages, consisting of two leaves. This structure is commonly used in bookbinding and manuscript creation. Each bifolium contributes to the overall construction of a book or codex by providing a simple, yet effective way to group pages together before they are sewn or bound.