Demonstrating background-clip

background-clip:
border-box;
background-clip:
padding-box;

In this example we have two small divs both, the first of which has background-clip set to border-box, the default, meaning the blue background extends to the outer edge of the border. In the second box, using padding-box clips the blue background to the outer edge of the padding (inner edge of the border), allowing the main background image to be partially seen.