Link Building is the process of generating links to your website for the purpose of building your site’s authority on search engines.
Any link from an external website that directs to a page or a website is referred to as a backlink. They’re a key aspect of SEO since they assist Google in figuring out which webpages are the most appropriate for specific queries. 

This occurs because these web pages have been connected to higher-ranking websites (referred to as backlinks) and outlines that the page is trustworthy and relevant.