SVG Sprites are fixed dimension, fixed colour vector based graphics, applied as the background of an html element in the same way a more traditional image based sprite works. As SVGs are vector based there is no requirement for alternative resolution versions for standard/retina displays.
For some background on this technique see this article by Chris Coyier.
<div class="Svg Svg-logo-small"></div>
Font based icons auto generated from SVGs.
<i class="Icons-calendar"></i>