In HTML, anything (including HTML) betewen "these" tags is considered
comment.
<!--this a comment-->
or
<!--
this is mutiline comment
this is mutiline comment
-->
The browser ingnores (does-not display) comments. But people who look at
the HTML can see them. Comments are used to provide info, remnders, or
guidance to the web authors (e.g., in templates or when multiple peopl
might work on a page) or to quickly add/remove or test changes.
For example, if you have a special banner and you don't want to show it
any more (but you don't want to remove it permenently), you comment-out
the HTML that calls the banner. Another example, you want see how a page
might look with a different stylesheet, you add the "links" to different
stylesheets and you comment them out except the one you want to test.
FP and other add web editors add HTML comments when you use certain
features.
...PC