how to cover a background image in css code example

Example 1: css background image cover center

html { 
  background: url(images/bg.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

Example 2: background image size css

#example1 {
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: auto;
}

#example2 {
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: 300px 100px;
}

Example 3: html background image fit to screen

body {
  background-position: center;
  background-repeat: no-repeat;
  background-size: contain;
}

Example 4: background image height and width

.class{
	background: url("../images/icons/map.png") no-repeat center center/50px 50px fixed;
}