Am I doing something wrong? In this image, it appears as if the ol is part of the term 1 description, but on my coding it's not.
my code:
<dl>
<dt>term 1 (definition list)</dt>
<dd>term 1 description</dd>
</dl>
<ol>
<li>ol list item 1</li>
<li>ol list item 2
<ul>
<li>ul list item 1</li>
<li>ul list item 2</li>
</ul>
</li>
</ol>
I'm not using any CSS
You're doing nothing wrong, it just looks that way in display. I've added a second element named "term2" in example below, and you can clearly see the elements are seperated. I'm sure it will look much more decent once you style it properly.