How do you get <code> to display>

As a general question, can someone please explain how to display code as written? For example, when I write, <code><h></code>, the preview omits the <h> tag in CodePen.

You could do it one of a couple of ways that I know. One is to use &lt; and &gt; to see < >

The other is to use javascript to replace the content with the same.

What do &lt; and &gt; stand for?