how to cover background image in whole page css code example

Example 1: css full cover background image

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

Example 2: how to cover whole webpage by background image in html

background: url(images/bg.jpg) no-repeat center center fixed; 
  background-size: cover;