When your users load a page, retina.js checks each image on the page to see if there is a high-resolution version of that image on your server. If a high-resolution variant exists, the script will swap in that image in-place.
The script assumes you use Apple's prescribed high-resolution modifier (@2x) to denote high-resolution image variants on your server.
For example, if you have an image on your page that looks like this:
<img src="/images/my_image.png" />
The script will check your server to see if an alternative image exists at this path:
"/images/my_image@2x.png"
via retinajs.com
