Folio in the context of "Paper size"

Recto is the "right" or "front" side and verso is the "left" or "back" side when text is written or printed on a leaf of paper (folium) in a bound item such as a codex, book, broadsheet, or pamphlet.

In double-sided printing, each leaf has two pages – front and back. In modern books, the physical sheets of paper are stacked and folded in half, producing two leaves and four pages for each sheet. For example, the outer sheet in a 16-page book will have one leaf with pages 1 (recto) and 2 (verso), and another leaf with pages 15 (recto) and 16 (verso). Pages 1 and 16, for example, are printed on the same side of the physical sheet of paper, combining recto and verso sides of different leaves. The number of pages in a book using this binding technique must thus be a multiple of four, and the number of leaves must be a multiple of two, but unused pages are typically left unnumbered and uncounted. A sheet folded in this manner is known as a folio, a word also used for a book or pamphlet made with this technique.

The size of a book is generally measured by the height against the width of a leaf, or sometimes the height and width of its cover. A series of terms is commonly used by libraries and publishers for the general sizes of modern books, ranging from folio (the largest), to quarto (smaller) and octavo (still smaller). Historically, these terms referred to the format of the book, a technical term used by printers and bibliographers to indicate the size of a leaf in terms of the size of the original sheet. For example, a quarto (from Latin quartō, ablative form of quartus, fourth) historically was a book printed on sheets of paper folded in half twice, with the first fold at right angles to the second, to produce 4 leaves (or 8 pages), each leaf one fourth the size of the original sheet printed – note that a leaf refers to the single piece of paper, whereas a page is one side of a leaf. Because the actual format of many modern books cannot be determined from examination of the books, bibliographers may not use these terms in scholarly descriptions.

Al-Baqarah (Arabic: الْبَقَرَة, ’al-baqarah; lit. "The Heifer" or "The Cow"), also spelled as Al-Baqara, is the second and longest chapter (surah) of the Quran. It consists of 286 verses (āyāt) which begin with the "muqatta'at" letters alif (ا), lām (ل), and mīm (م). The Verse of Loan (the longest single verse of the Quran), the Throne Verse (the greatest verse), and the last 2 verses, Treasures of the Throne are in this chapter.

The sūrah encompasses a variety of topics and contains several commands for Muslims such as enjoining fasting on the believer during the month of Ramadan; forbidding interest or usury (riba); and several other famous verses such as the last two verses, which came from the treasure under Allah's Throne, and the verse of no compulsion in religion.The sūrah addresses a wide variety of topics, including substantial amounts of law, and retells stories of Adam, Ibrahim (Abraham) and Mūsa (Moses). A major theme is guidance: urging the pagans (Al-Mushrikeen) and the Jews of Medina to embrace Islam, and warning them and the hypocrites (Munafiqun) of the fate God had visited in the past on those who failed to heed his call. The surah is also believed to be a means of protection from the jinn.

The earliest texts of William Shakespeare's works were published during the 16th and 17th centuries in quarto or folio format. Folios are large, tall volumes; quartos are smaller, roughly half the size. The publications of the latter are usually abbreviated to Q1, Q2, etc., where the letter stands for "quarto" and the number for the first, second, or third edition published.

The Passages d'outremer is a chronicle of the crusades written in Middle French by Sébastien Mamerot in 1473–1474. Drawing freely on legendary material, it covers the wars between Catholics and Muslims from the time of Charlemagne until 1462.

Mamerot was the chaplain of Louis de Laval-Châtillon, governor of Genoa, who commissioned the Passages. It is divided into 88 chapters and covers 272 folios in manuscript. Its full title is Passages fais oultre mer par les François contre les Turcqs et autres Sarrazins et Mores oultre marins ('Passages made overseas by the Franks against the Turks and other overseas Saracens and Moors').