Also known by a variety of terms related to incoming Web traffic, a backlink is basically any link received by one Web page or other Web node from another. These links are placed on websites to point back to pages on another website. Backlinks indicate to Google, for example, how popular a page is by the number of times it is visited, which in part determines its PageRank, or where it resides on the list of results when someone searches for its keywords. Backlinks also signal who is paying attention to that page.

Quality backlinks are important to avoid penalties for unintentionally violating Google’s PageRank algorithms. They must be strategically placed on reputable Web sites with quality content that is free of keyword stuffing, for example. The more reputable the websites that work in your favor, the less the number of links that will need to be posted on lower quality and ranking websites.