One of the major traps, when talking about type, is mixing up fonts with typefaces or treating them as synonymous. Many a typographic expert has haughtily corrected a beginner for mistakenly using the word font when he or she should have said typeface. To those of us who think about fonts only when choosing one in Microsoft Word, the distinction between the terms can seem confusing, esoteric, and even arcane.

In brief: A font is what you use, a typeface is what you see.

Back in the good old days of analog printing, every page was laboriously set out in frames with metal letters. That was rolled in ink, and then it was pressed down onto a clean piece of paper. That was a page layout. Printers needed thousands of physical metal blocks, each with the character it was meant to represent set out in relief (the type face). If you wanted to print Garamond, for example, you needed different blocks for every different size (10 point, 12 point, 14 point, and so on) and weight (bold, light, medium).

Image: Metal type via Flickr user Malene Hald

This is where we get the terms typeface and font. In the example above, Garamond would be the typeface: It described all of the thousands of metal blocks a printer might have on hand and which had been designed with the same basic design principles. But a font was something else entirely. A font described a subset of blocks in that very typeface–but each font embodied a particular size and weight. For example, bolded Garamond in 12 point was considered a different font than normal Garamond in 8 point, and italicized Times New Roman at 24 point would be considered a different font than italicized Times New Roman at 28 point.

The distinction between the two terms, and the processes they encapsulated, got muddied with the rise of desktop publishing. Fonts were no longer thousands of tiny blocks of movable type; they became digital computer files that scaled themselves up or down dynamically to whatever size or weight users wanted. So the distinction between process and end result disappeared in a puff of binary magic for most people.