DataTransfer.getData()

getData(format);

<div id="div1" ondrop="drop(event)" ondragover="allowDrop(event)">
  <span id="drag" draggable="true" ondragstart="drag(event)"
    >drag me to the other box</span
  >
</div>
<div id="div2" ondrop="drop(event)" ondragover="allowDrop(event)"></div>

#div1,
#div2 {
  width: 100px;
  height: 50px;
  padding: 10px;
  border: 1px solid #aaaaaa;
}

function allowDrop(allowdropevent) {
  allowdropevent.target.style.color = "blue";
  allowdropevent.preventDefault();
}
function drag(dragevent) {
  dragevent.dataTransfer.setData("text", dragevent.target.id);
  dragevent.target.style.color = "green";
}
function drop(dropevent) {
  dropevent.preventDefault();
  const data = dropevent.dataTransfer.getData("text");
  dropevent.target.appendChild(document.getElementById(data));
  document.getElementById("drag").style.color = "black";
}