The _footer.pcf file was created to add an area at the bottom of your site. The site footer can be turned on/off per page, and you can add footers to sub-folders if your site. Any files in the sub-folder will pick up that footer instead of the one at the root of the site. Footers appear at the very bottom of the page, before the main WKU footer.
The _footer.pcf file allows full WYSIWYG content editing, so you can add anything you need. A common use for the site footer is contact or social media information, using snippets. The footer on this page is being used to display a heading, description, and link to get help with OU Campus.