Backlinks are link connections from the pages of one website to another. Google uses backlinks as a crucial factor for determining how your web pages will rank on search engines. They help Google understand that the content of your pages is credible and valuable.
Even though Google keeps making changes to its algorithms, backlinks have always remained a crucial ranking signal. One quality backlink has more value than several hundreds of low-quality ones. A good backlink should come from an authoritative and trusted site and it should include your target keyword in the link’s anchor text.
Unnatural Links
Backlinks may be natural or unnatural based on how they are gotten. Unnatural links are often bought and are usually of low quality and irrelevant to the content of the web page.
To manage the growth of unnatural links, Google uses its penguin algorithm to penalize sites that source their backlinks through unnatural means. Unnatural links can be paid links, links exchanged for some purpose.