What's the Difference between a Font and a Typeface?

Aren’t they the same thing?
After being shot down by an over enthusiastic designer for calling a typeface a font to a client over the phone this particular developer would now disagree. You see to Joe Bloggs A type and a Font are the same thing, to a developer it’s like saying a Gerbil and a Hamster are the same thing. To them they’re both a small, furry and sometimes smelly caged pet. A designer of the other hand is a little pickier when it comes to detail, after all they are trained to look at the smallest details. He would say to the developer..

“A Gerbil is nothing like a Hamster, Hamsters for a start like to live alone and seem to wake up when you go to sleep. Gerbils on the other hand are the complete opposite, they are happiest in groups and love being active, chewing and gnawing at the bars till you play with them.”

So yes, fonts and typefaces are technically different though relate to the same thing.

What is a typeface?
Think of a typeface as the ‘design’ of 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 “Garamond” you’re talking about a set of letters in a specific style, a ‘typeface’.

What is a font?
Think of a font as 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.

Adobe’s type glossary description
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.

F*** you designer snob!
Next time you encounter a stuck up designer who likes to take every opportunity to correct you on design related jargon, just think, here’s one small dollop of typography info to counter his attacks. I’d be so blunt as to knowingly misdescribe the font/typeface then counter his verbal nonsense with your new found knowledge.
http://www.thefloatingfrog.co.uk/tips-tricks-tutorials/what-is-the-difference-between-a-font-and-a-typeface/