HTML Guide for contentinfo

The <footer> element represents a footer for its nearest sectioning content, and has an implicit role of contentinfo, so specifying this role is redundant.

The following example marks a <div> as a footer specifying its role:

<div role="contentinfo">
  <h2>Footer</h2>
  <!-- footer content -->
</div>

Using the <footer> element instead is recommended:

<footer>
  <h2>Footer</h2>
  <!-- footer content -->
</footer>