What is the difference between `firstChild` and `firstElementChild`?

Question

I am learning about DOM, and I can't understand: What is the difference between firstChild and firstElementChild?

Answer 1

The difference between this property and firstChild, is that firstChild returns the first child node as an element node, a text node or a comment node (depending on which one's first), while firstElementChild returns the first child node as an element node (ignores text and comment nodes).

for more info : HTML DOM firstElementChild

In the example below, you can see that firstChild returns the comment node and firstElementChild returns the element child i.e <li> A </li>

const ul = document.querySelector( 'ul' );

console.log( ul.firstElementChild );
console.log( ul.firstChild );

<ul><!--This is a comment node-->
        <li> A </li>
        <li> B </li>
        <li> C </li>
    </ul>