Backlink is an active hyperlink that locates on web sites and refers to the original online resource. Often the text of such links includes retrieval request which uses for site optimization in search systems. Two main types of backlinks Natural. Method of obtaining natural backlinks allows you to get them for free, but the time needed to accumulate sufficient referential mass is quite long. Artificial. It is a method in which an SEO expert gets a link back to the site by paying money. This technique is called automatic promotion. In this case, an SEO expert practically does not spend time on the selection of sites where it will buy links.