It is making use of a styling element called "@font-face".

Use it like this:

• Google "WebFont", and look for free fonts to download as .ttf (truetype) or .otf (opentype).
• Upload the font to your website, noting the path where it's saved.
• Include something like this definition in your css:
  
  @font-face {
  font-family: breipfont;
  src: url(breipfont.otf) format("opentype");
  }
  
  
• Then you can just use it in a style selector like any other font:

  body {
  font-family: breipfont, Geneva, sans-serif;
  }