Better CSS Font Stacks

You want to use Gill Sans? Go right ahead. Nothing should stop you. Font stacks are prioritized lists of fonts, defined in the CSS font-family attribute, that the browser will cycle through until it finds a font that is installed on the user’s system. This means that you can use Gill Sans, and if your users don’t have it, you can give them an adequate substitute that will not diminish their experience.

Ford, Nathan. Unit Verse (2008). Articles>Web Design>Typography>CSS