This is unpadded green content with a 1px border. It is positioned at 0,0
relative to the outer container. The result shows that position is measured from inside the outer container's (cyan) border and ignores the outer container's (yellow) pad.

This is unpadded red content with a 1px border. It is not positioned relative to the outer container. Beyond the border of the ed content is the outer container's yellow pad, which pushes the red content down and to the right.