For example, I can specify CHANGES to top, bottom, right, and left pixel position for relative divs. That element will be moved from its current position based on the values given to top, bottom, right, and left. Unfortunately, they only visually move. The occupied space is still occupied. So, they're mostly useless.

I can also use z-index to set the layer order for the element (which element is on top). Z-index only works when an element is positioned (absolute, relative, or fixed). Highest z-index value goes on top!

Use CSS to move these elements around from their normal position. What will happen if you set the red div's top to -15px? What will happen if you set the black div's left to -20px? Experiment and understand.

To get credit, You must use images with transparent backgrounds!