how to fill img code example

Example 1: is there an img cover

body {
  margin: 0;
}
img {
  display: block;
  width: 100vw;
  height: 100vh;
  object-fit: cover;
}

Example 2: 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;
}