Box filler property is using to change the height and width of element.
Since css2, the box property has worked like as shown below −
width + padding + border = actual visible/rendered width of an element's box
height + padding + border = actual visible/rendered height of an element's box
<html>
<head>
<style>
.div1 {
width: 200px;
height: 100px;
border: 1px solid blue;
}
.div2 {
width: 200px;
height: 100px;
padding: 50px;
border: 1px solid yellow;
}
</style>
</head>
<body>
<div class = "div1">techedhub.com</div><br/>
<div class = "div2">techedhub.com</div>
</body>
</html>