Instead of including FA's stylesheets and fonts, you just have an SVG with some defs. Instead of having a <i class=...></i> to use an icon, which CSS turns int

Instead of including FA's stylesheets and fonts, you just have an SVG with some defs. Instead of having a <i class=...></i> to use an icon, which CSS turns into a specific character with a specific font name, which the font turns into a specific glyph from that font (usually SVG), you have a <svg><use ...></svg> You can use the same icon because FA is already using SVG fonts, you can copy and paste the icons out.