A footer link is a hyperlink that is positioned at the base (or bottom) of a website. Footer links are primarily used to supply visitors with supplemental information about the site, such as contact details, sitemaps, and copyright notices. In certain instances, they can also serve navigational purposes.
From an SEO perspective, footer links are often viewed as more valuable than other types of internal links because they appear on every single page of a website. Consequently, they receive far more internal linking signals compared to, say, a single internal link embedded within a blog post.
When links to other sections of the site are accessible in the footer, users can more easily navigate to different areas of the website without needing to return to the homepage. In this way, footer links can also enhance the overall usability of a website.