Yeah, "<--" is HTML for "Please ignore this, Mr Browser. I'm just posting a note for myself in the HTML code, probably to help me find this location later or to tag it in the text editor so I'll know where this part of the web page is located".  Everything after <-- is ignored and not posted on the page. It's closed with "-->" at the end which tells the browser, "Okay, I'm done. Go on about your business" :)

"A friend is an enemy who hasn't got the GUTS to KILL you!" - Judy Tenuda