Hyperlinks that are attached to a target on another domain besides the one associated with the link is called an external link. In simpler terms, it’s a website that is linked to your website. These links are considered external links because they are located outside the domain. Also, If you connect to a website using content on your site, this is too considered an external link. To create the ideal external link, you should use descriptive language that is specific to your site called keywords. While you do need to insert these keywords into your text, you do not need to use them excessively. Multiple text anchors will increase their performance and accessibility to your end user.
An external link connects a web page to an external site or domain. According to leading SEO contributors, external links are an integral part of increasing ranking power because they pass along their credibility and search engine reputation in the link. These theories further the opinion of many in the SEO community that a website’s reputation is more important than what is being said on a website.
Most SEO writers agree that managing your external links is the most helpful metric to control when attempting to increase your rankings. While it is helpful to know that external links are most likely the leading contributing factor to search engine rankings, it also bears mentioning that it’s one of the most difficult tactics to manipulate. It’s nearly impossible to know if your site will be linked to external content, so this particular metric is cleverly used by search engines to gauge the true popularity of a website. Google has perfected the use of this method after borrowing the tactic from Alta Vista. According to the PageRank algorithm, external links are likened to web page popularity votes. This initial methodology of the Google algorithm has become more complex as time has progressed, but external links remain a very strong determinative value when ranking websites.
major search engines use a varied number of metrics to establish a value and efficacy of external links and their ability to pass along value to connected sites.
Metrics that factor into the ranking power of an external link include:
Trustworthiness – the credibility of a webpage, which is determined by how many other trustworthy sites it is connect to through hyperlinks.
this refers to the current established popularity of the linking page that will factor into any passed along ranking boost it could lend to a connected page.
the source page and the linked target page should have similarity in content or the two pages should share relevancy of topic.
the content used to attach the linked URL should have relevancy and keywords associated with the content subject matter.
The number of time a source page is linked to the same page can also factor into the determining the value of an external link. If the target page also has a large quantity of domains that link to it, then that is a positive sign of the value of the external link. Additionally, if the source and target domains have a shared relationship, this is also considered a factoring metric.
External links are a very large piece of this puzzle because of popularity and relevancy. These two reasons are important because the Internet is constantly changing, with content being added at a high frequency. Knowing what is popular and relevant helps create accurate search engine results page (SERPs.)
External links are a great means of determining website popularity because traffic numbers are unreliable. Traffic calculations provide a challenge for search engines because they usually need privately held information that has to be requested. External links are easily researched public data.
Anchor text is the relevant content typically created by a human writer that provides clues to the search engine algorithm with regards to the information on any given page. Search engines also search for relevancy clues linked in the target and source pages. The cited domain also provides a metric that the search engine can use to determine the content and associated relevancy. Anchor text is usually very short phrases that provide helpful insight into the subject matter of a web page. These links also help connect associated content, which helps establish understanding in the search engine databases across the Internet. It also helps establish and rank documents by importance.
- Google's Official Guidelines for Webmasters. Webmaster Guidelines