A computer font is implemented as a digital data file containing a set of graphically related glyphs. A computer font is designed and created using a font editor. A computer font specifically designed for the computer screen, and not for printing, is a screen font.
In the terminology of movable metal type, a typeface is a set of characters that share common design features across styles and sizes (for example, all the varieties of Gill Sans), while a font is a set of pieces of movable type in a specific typeface, size, width, weight, slope, etc. (for example, Gill Sans bold 12 point). In HTML, CSS, and related technologies, the font family attribute refers to the digital equivalent of a typeface. Since the 1990s, many people outside the printing industry have used the word font as a synonym for typeface.