HTML comments are not displayed in the browser, but they can help document your HTML source code. There is an exclamation point (!) in the start tag, but not in the end tag.
Ex: <!-- Write your comments here -->
With comments, you can place notifications and reminders in your HTML code.
Ex: <!-- This is a comment -->
<p>This is a paragraph.</p>
<!-- Remember to add more information here -->
<p>This is a paragraph.</p>
<!-- Remember to add more information here -->
Comments can be used to hide content.
Ex: <p>This is a paragraph.</p>
<!-- <p>This is another paragraph </p> -->
<p>This is a paragraph too.</p>
<!-- <p>This is another paragraph </p> -->
<p>This is a paragraph too.</p>
You can also hide more than one line, everything between the <!-- and the --> will be hidden from the display. Comments are also great for debugging HTML, because you can comment out HTML lines of code, one at a time, to search for errors.
Ex: <p>This is a paragraph.</p>
<!--
<p>Look at this cool image:</p>
<img border="0" src="pic_trulli.jpg" alt="Trulli">
-->
<p>This is a paragraph too.</p>
<!--
<p>Look at this cool image:</p>
<img border="0" src="pic_trulli.jpg" alt="Trulli">
-->
<p>This is a paragraph too.</p>
Comments can be used to hide parts in the middle of the HTML code.
Ex: <p>This <!-- great text --> is a paragraph.</p>