The term "folio", from the Latin folium (leaf), has three interconnected but distinct meanings in the world of books and printing. It is firstly a term for a common method of arranging sheets of paper into book form, folding the sheet only once, and a term for a book made in this way. Secondly it is a general term for a sheet, leaf or page in (especially) manuscripts and old books, and thirdly an approximate term for the size of a book, and for a book of this size.