shortcut to add comment in html code example

Example 1: html how to add comment

<!-- This is the first comment, it won't be shown on a page -->

<h1>And this is a header. It will be fully visible.</h1>

<!--
Multiline comment.
You can place a lot of information there.
Maybe even a whole book.
-->

Example 2: how do i comment in htmle

<div>
<p>This text is visible. Check the source code for multi-line comment.</p>
<!--  
Hello, world! I am a comment and I am
displayed in multiple lines!
--> 
</div>