CSS Sprites is a technique where you use a background-image, a set width and height, and adjust the background-position to display only the portion you need to show. This way you can use a single image and display lots of different graphics with it, saving server requests and speeding up page load times. The “sprite” is the single, combined graphic. We can use this same theory, only instead of using background-image to show the graphic, we can use an image right in the HTML itself (inline image).
Skeleton is a small collection of CSS & JS files that can help you rapidly develop sites that look beautiful at any size, be it a 17” laptop screen or an iPhone.