First and foremost when talking about fonts, you must understand the difference between typefaces and fonts. Typefaces are the design or look of the text being used, while the font is the delivery method of that typeface.
Stephen Coles from FontFeed explains it in terms of music:
When you talk about how much you like a tune, you don’t say: “That’s a great MP3”. You say: “That’s a great song”. The MP3 is the delivery mechanism, not the creative work; just as in type a font is the delivery mechanism and a typeface is the creative work.
Another way to show this difference is to literally show you the anatomy of type(faces) vs the anatomy of fonts.
The Anatomy of Type
The Anatomy of Font
Fonts can often times be a tricky and frustrating component of design and development for the web. Designers and developers face licensing and font compatibility issues across operating systems; not to mention browser compatibility issues.
Traditionally fonts were only sold with rights to print, with no mention of their use on the web. Thus, websites have been limited to a few selections of font families that work across different operating system and browsers.
Another problem fonts face is that not all fonts work across different operating systems and browsers. Operating systems such as iOS and OSX generally do not have problems rendering the two main font types, PostScript and TrueType. Meanwhile, Windows operating systems have had some difficulties rendering PostScript fonts over the years.
Font foundries are now making “web safe” fonts, which contain additional information required by different operating system and browsers. This coupled with the fact that different OS’s are becoming more friendly to all font types, is making this issue easier to solve for developers.
As more fonts become web friendly, font embedding with CSS is being utilized more and more. This is greatly expanding the diversity of fonts that can be used on the web. With easier methods to include different fonts, I believe we’ll see even more uses of selectable typography and visually more interesting websites. I also believe that we’ll see even more influence from print design bleed over onto the web, where traditionally typography-rich designs were too problematic to build.