Backlink (Inbound Links) - links to your website from external websites that are not on your domain. Backlinks are used by SEO to increase the authority of the site in the eyes of search engines, which allows it to increase in the search results.
Google and other major search engines consider backlinks “votes” for a specific page. Pages with a high number of backlinks tend to have high organic search engine rankings.
Using links in a search engine algorithm is nothing new. In fact, backlinks formed the foundation of Google’s original algorithm (known as “PageRank”).
Earning backlinks is an essential component of off-site SEO. The process of obtaining these links is known as link earning or link building.