The read-only nodeName property of Node returns the name of the current node as a string.

A string. Values for the different types of nodes are:

Attr

The value of Attr.name, that is the qualified name of the attribute.

CDATASection

The string "#cdata-section".

Comment

The string "#comment".

Document

The string "#document".

DocumentFragment

The string "#document-fragment".

DocumentType

The value of DocumentType.name

Element

The value of Element.tagName, that is the uppercase name of the element tag if an HTML element, or the lowercase element tag if an XML element (like a SVG or MATHML element).

ProcessingInstruction

The value of ProcessingInstruction.target

Text

The string "#text".

This example displays the node names of several nodes

This is some HTML:
<div id="d1">Hello world</div>
<!-- Example of comment -->
Text <span>Text</span> Text<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">Not calculated yet.</output>

and the following script:

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

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

• Element.tagName
• Attr.name
• DocumentType.name
• ProcessingInstruction.target