SVG (Scalable Vector Graphic) has been available for a long time, but somehow this technolgy is abit under used. The most important reason is the compatibility, but with all current modern browsers, this shouldn't be an issue anymore.
There are a few obvious advantages such as vector graphic can be scaled to any size without having a pixelated image. SVG image will look great on those devices with retina displays. Finally, you can add interactions on it.
You can generate SVG easily using Snap.svg, and you can also use Snap to work with SVG generated from tools like Adobe Illustrator, Inkscape, or Sketch. You can even load strings of SVG asynchronously and query out the pieces you need in order to turn SVG files into sprite sheets. Snap.svg has a great documentation too, that's the most important thing to all the developers!