Background Repeat | Images
If the background image is smaller than the element, the image will repeat itself, horizontally and vertically, until it reaches the end of the element:
<!DOCTYPE html>
<html>
<head>
<title>Background Repeat</title>
</head>
<body>
<h2>Background Repeat</h2>
<p>By default, the background image will repeat itself if it is smaller than the element where it is specified, in this case the body element.</p>
</body>
</html>