In traditional Typography, a complete set of metal sorts comprising all the characters of a single Typeface in one specific size and style, cast as a unit for composition. The word derives from the French fonte, meaning "something cast." In digital usage, a font is the software file (e.g., PostScript, TrueType, or OpenType) that contains the outlines and metrics needed to render a typeface on screen or in print. Where a typeface is a design, a font is its physical or digital instantiation.