title: Understand different drag and drop parameters?
body: <p>I am looking at <a href="https://www.w3schools.com/html/html5_draganddrop.asp" rel="nofollow noreferrer">https://www.w3schools.com/html/html5_draganddrop.asp</a> and
  I'm trying to understand why ondragstart = "drag(event)" works but not "drag(ev)"?</p>
  
  <p>`function drag(ev) {
    ev.dataTransfer.setData("text", ev.target.id);
  }</p>
  
  <p>`</p>