Backlinks are especially valuable for SEO because they represent a “vote of confidence” from one site to another.
In essence, backlinks to your website are a signal to search engines that others vouch for your content. If many sites link to the same webpage or website, search engines can infer that content is worth linking to, and therefore also worth surfacing on a SERP. So, earning these backlinks can have a positive effect on a site’s ranking position or search visibility.