how to add image to the background in ccss code example

Example 1: add background image in css

.w {
background-image: url("images/tom1.png");
}

.a {
background-image: url("images/tom2.png");
}

.s {
background-image: url("images/tom3.png");
}

Example 2: ho to add background image in css

body {
  background-image: url("img_tree.gif"), url("paper.gif");

    background-color: #cccccc;
}