Node: nodeName

 HTML 
<div id="d1">Hello world</div>
<!--  -->
<span></span> <br />
<svg height="20" width="20">
  <circle cx="10" cy="10" r="5" stroke="black" stroke-width="1" fill="red" />
</svg>
<hr />
<output id="result"></output>

let node = document.querySelector("body").firstChild;
let result = ":<br/>";
while (node) {
  result += `${node.nodeName}<br/>`;
  node = node.nextSibling;
}

const output = document.getElementById("result");
output.innerHTML = result;