In typography, a font is traditionally defined as a quantity of sorts composing a complete character set of a single size and style of a particular typeface. For example, the set of all characters for 9-point Bulmer italic is a font, and the 10-point size would be a separate font, as would the 9-point upright.
After the introduction of computer fonts based on fully scalable outlines, a broader definition evolved. Font is no longer size-specific, but still refers to a single style. Bulmer regular, Bulmer italic, Bulmer bold and Bulmer bold italic are four fonts, but one typeface.
However, the term font is also often used as a synonym for typeface. http://www.en.wikipedia.org/wiki/Font
Typeface
The art and craft of designing typefaces is called type design. Designers of typefaces are called type designers, and often typographers. In digital typography, type designers are also known as font developers or font designers. http://www.en.wikipedia.org/wiki/Typeface
