document object model it is interface for web documents
<div id="box" style="width: 50px; height: 50px; background: green; position: absolute; top: 50px; left: 50px;"></div> <button onclick="moveRight()">Move Right</button> <script> function moveRight() { let box = document.getElementById("box"); let left = parseInt(box.style.left) || 0; box.style.left = (left + 50) + "px"; } </script>