HTML comments is the very important for Web designer. You can add comments to your HTML source page by using the following syntax:
<!-- Write your comments here --> right comment.
<!-- Write your comments here --> wrong comment.
Comments never display on your browser (Comment use designer for understanding your source file when see it after long time).
Conditional Comments:
You might stumble upon conditional comments in HTML:
<!--[if IE 8]>
.... some HTML here ....
<![endif]-->
