21_comments.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title goes here</title>
</head>

<body>
    <h2>Comments</h2>

    You will be able to see this text. 
    <!-- You will not be able to see this text. --> 

    You can even comment out things in <!-- the middle of --> a sentence. 

    <!-- Or you can 
        comment out a large 
        number of lines. --> 

    <div class="example-class"> Another thing you can do is put comments after closing tags, to help you find where a particular element ends. <br> (This can be helpful if you have a lot of nested elements.) 
    </div> <!-- /.example-class -->

</body>

</html>