Why there is no tree tag in html?

Question

Hi, I wonder why there is no tree tag in html? Something like table tag.

For example:

<tree>
  <treenode id=root>
    <treenode id=child1 />
    <treenode id=child2>
       <treenode id=child2-1>
       ......
       </treenode>
    </treenode>
  </treenode>
</tree>

Answer 1

There is. Nested lists (ul, or ol).

<ul>
    <li>foo</li>
    <li>bar</li>
    <li>test
        <ul>
            <li>foo</li>
            <li>bar</li>
        </ul>
    </li>
    <li>example</li>
</ul>

And with the help of CSS and JS you can make the tree look and interact like, for example, the windows explorer.