This is a special Web Font that has hundreds of icons as special characters. This is very useful on certain websites, like this one, where numerous icons are used. Since they work like regular web characters, they can be different colors, sizes, and they can even have a shadow.
The Awesome Font does add to the initial page weight, so it should not be used unless there are some special benefits. Here are the icons available if Awesome Font is used:
Printed from jwebs.bz (Options, Awesome Font - JWebs)