Answers for "how do I make the background image cover the entire screen"

css background image size to fit screen

html {
    height: 100%
}
body {
    background-image:url("../images/myImage.jpg");
    background-repeat: no-repeat;
    background-size: 100% 100%;
}

how to cover full background with css

<div id="bg">
  <img src="images/bg.jpg" alt="">
</div>