In the World Wide Web, a backlink is a reference from a third-party website to one's own website. Backlinks are inbound links and therefore an important criterion for the evaluation of websites. They also generate additional traffic from the third-party website to the corresponding landing page.
Since backlinks link from a website to a website, they are evaluated by search engines as recommendations. The quantity of backlinks determines the link popularity and, together with the quality of the backlinks and the link text, is included in the search engine ranking. The quality of the backlinks is determined by the PageRank of the website from which the backlink is made and also from whether the link text of the backlink contains keywords. As far as link popularity is concerned, the search engine algorithms are set in such a way that if many web pages refer to a certain website, it must also have a high topic relevance.
If the backlink from the foreign website is directly to a specific own website or to a specific article on such a landing page, we speak of deep links.