CSS

background image css fill screen

.Background {
  background-image: url("Your picture name.jpg");
  background-repeat: no-repeat;
  height: 100%;
  background-position: center;
  background-size: cover;
}

CSS make image fill whole background

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;
}

background image fill div

div {
	background-image: url("example.com/image.png");
    background-repeat: no-repeat;
    background-size: cover;
}

css full cover background image

body { 
  background: url(path/to/bg-image.jpg) no-repeat center center fixed;
  background-size: cover;
}

css fill div with background image

div {
  background-image: url("example.com/image.png");
  background-size: 100% 100%;
}