title: What's the ::before and ::after that I see in the HTML element inspector?
body: <p>Our sites use markup like this in a few places:</p>
  
  <pre><code>&lt;header class="row"&gt;
    ::before
    &lt;h1 class="entry-title"&gt;Privacy Policy&lt;/h1&gt;
    ::after
  &lt;/header&gt;
  </code></pre>
  
  <p>What does the <code>::before</code> and <code>::after</code> signify and how could I use them?</p>