How do you determine the difference between a font and a typeface?

Typeface: is the design of the alphabet--the shape of the letters that make up the typestyle. The letters, numbers, and symbols that make up a design of type. So when you say “Arial” or “Goudy” you’re talking about a set of letters in a specific style.

Font: is the digital file that contains/describes the typeface. Think of the font as a little piece of software that tells the computer and printer how to display and print the typeface.

A typeface family is a group of typefaces that were designed to be used together. For example, Goudy Old Style has Roman (upright or normal), italic (slanted and cursive), bold and bold italic versions. Each of the style and weight combinations is called a face or typeface, and together they are, hopefully, a happy typeface family (rather than a dysfunctional typeface family which will probably be more familiar to you).

According to Adobe’s type glossary: “A font is one weight, width, and style of a typeface. Before scalable type, there was little distinction between the terms font, face, and family. Font and face still tend to be used interchangeably, although the term face is usually more correct. A typeface is the letters, numbers, and symbols that make up a design of type. A typeface is often part of a type family of coordinated designs. The individual typefaces are named after the family and are also specified with a designation, such as italic, bold or condensed.

John

Jack

Tom

Here, you see a family of three twins: John Smith, Jack Smith, and Tom Smith. Each brother shares the same face, but their weights vary – read: one is slim, the other is rather rotund.

Together, the brothers make up the Smith family.

Typographically, John, Jack, and Tom are each fonts and together they make up the Smith typeface.