What’s the difference between HTML Comment and JSP Comment.

The difference between HTML/XML(Markup) comments and JSP comments is that the JSP translator doesn't recognize the former as comments and treats them as template text while the later is stripped out of translated JSP Page.

HTML comments are sent to the client but are not displayed by the browser. A user can still view these comments by viewing the source HTML for the page. JSP comments are stripped by JSP translator at page translation time.