This is an example of a picture set at Relative position

The pic inside the blue box is positioned relative to the blue box at 50px from the top and 50px from the left of inside the blue box. That means that the box can be positioned anywhere on the browser, but the pic will always stay in the same position relative to the blue box.

* Adjust the browser windows size to make the blue box move and watch how the pic stays in the same position inside the box