self contained content element code example

Example: html semantic

<div></div>
    <span></span>
    <hr> <!-- horizontal rule is a divider -->
    <br> <!-- break make a break line -->
    <sup></sup> <!-- superscript add a notation (upp) -->
    <sub></sub> <!-- subscript add a notation (down) -->
    &lt; <!-- &; is used to print special or reserved character 
    &lt; = “<” and &gt; = “>” -->