how to set a div on image in css code example

Example 1: How to set a image as a backgroung image

<style>
body {
  background-image: url('img_girl.jpg');
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
}
</style>

Example 2: how to set div background image

body {
 background-image: url("paper.gif");
 background-color: #cccccc;
}