1. Logical or Linear Ordering
Most languages read and process top-to-bottom, so it’s vital to list them linearly or logically down the page.
  HTML
<!DOCTYPE html>
<html>
  <body>
    <!-- This is improper ordering of blocks! -->
    <!-- The footer should come after the main content. -->
    <footer>
      <p>(C) School of Media Arts</p>
    </footer>
    <main>
      <h1>"Old Town Road"</h1>
      <h2>Yeah, I'm gonna take my horse to the old town road.</h2>
      <i>Lil Nas X</i>
    </main>
  </body>
</html>
development