Link building is the practice of acquiring links to your website from other websites. In SEO, these links are called backlinks. Getting backlinks from high-quality sites can pass authority to your site, as well as help you rank higher in the search engine results pages (SERPs).
According to Google, an important part of identifying what pages are relevant and trustworthy is “understanding if other prominent websites link or refer to the content.”
Because of this, it’s important to consider link building when building an SEO strategy.