Backlinks, also known as inbound links are offsite links that lead to another owner’s website or web page. Their importance lies in search engine optimization or SEO. The number of backlinks is supposedly one of the indicators used by Google in determining the rank of a website or an individual web page.
The number of backlinks that a website has been, over the years, a major focus by new SEO practitioners. Unfortunately, that sometimes leads to a practice called Link Farming. This is the practice of a group of websites that link to every other website in the group. A problem arises from that practice in that the links are of low quality. This can and usually does lead to any website receiving a back link from a Link Farm to be banned from the search engines. Google interprets a link from page A to page B as a vote, by page A, for page B.
Several things determine the worth of a backlink. Authority of linking websites on a particular topic are assigned a value. If both sites have content geared toward the keyword topic, the backlink is considered relevant. This is believed to influence the search engine rankings of the web page granted the backlink. A backlink represents a “thumbs up” for the content on the webpage from the external webpage. Another factor is the anchor text of the backlink. Anchor text is the text used in the creation of the hyperlink as it appears on a web page. The search engine spiders examine the anchor text to evaluate how relevant it is to the content on a webpage. The Anchor text and its use (placement, context) within the webpage content are highly weighted in search engine results page (SERP) in regards to any search query.