You can use the z-index property together with the position property to create layers like in Photoshop. Normally, HTML elements are considered 2D, having only width and height. The z-index property introduces the new dimension — depth, and its value specifies the stack level of the box. Browsers display elements with higher values on top of elements with lower values.

In the example, the yellow element's z-index value is 1, and the header's z-index value is unspecified, which defaults to 0. As 1 is higher than 0, the yellow element overlays the header.