How can you overlay two elements with background images in CSS?

To overlay two elements with background images in CSS, you can use the `position: absolute` property to position the elements on top of each other. Make sure the parent element has `position: relative` set to establish a positioning context. You can then adjust the `z-index` property to control the stacking order of the elements. ```css .parent { position: relative; } .element1, .element2 { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } .element1 { background-image: url('image1.jpg'); z-index: 1; } .element2 { background-image: url('image2.jpg'); z-index: 2; } ```