In addition to on-page SEO, your site also needs off-page SEO. This type of SEO includes factors outside of your website that you don’t control directly. The most notable off-page SEO tactic is earning backlinks.
Backlinks are links to your site from other websites. Google uses the quantity and quality of links to your site to determine its reputability and relevancy, which impacts search result rankings. Backlinks also help Google find pages on your site, crawl, and index them.