I use <! comment > and it still works. Why? Samething with <hr>

Answer 1

The comment tag <!-- comment here --> will not be read by the browser. It is used to document any particular comments you have in your code. Notice the exclamation mark ! in the beginning of the tag, this lets the browser know that this tag isnt just an ordinary tag. For the hr tag try <hr/>. Hope this helps!!

Answer 2

for comment ... use <!-- your comment --> and it will not be shown on the browser ...
we use </hr> without <hr> (only closing tag)