Using external fonts with HTML5 Web Fonts
Before the introduction of Web fonts, we did not have much control over the font that our text would be served in. We had to provide multiple fonts as fallbacks in the case the system of the user does not support our desired font and even specify a font family like serif or sans-serif if none of our desired fonts were available to the user. It was best to rely on several web-safe fonts such as Georgia, Times New Roman or Arial (to see the web-safe fonts, visit http://www.w3schools.com/cssref/css_websafe_fonts.aspp) . HTML5 allows us to add any font to our website and if the user supports Web fonts the font would be downloaded by the user automatically. This happens with the help of the @font-face rule.
Note: If you Un-Subscribe from feed you will not able to download any source.
Source: PHPGang