Sometimes called an inbound link (IBL), a backlink is a term used to describe an external hyperlink that directs traffic from one website to another. In search engine optimization (SEO), a backlink is important in signaling the relevance of a web page to a search engine. A page’s search ranking is often impacted by backlinks because they add a layer of credibility in the eyes of search engines like Google, Bing, and DuckDuckGo.
Types of backlinks
Although the difference is negligible to the untrained eye, there are two types of backlinks (dofollow and nofollow links) that have significant implications for a website’s SEO ranking.
Dofollow backlinks are the most common type of link because they don’t require any extra HTML code. They simply hyperlink text or an image, which search engines interpret as an organic relationship between sites. This adds credibility to the site that publishes the backlink as well as the host of the backlink itself because both sites are seen as providing quality content that is relevant to a specific audience.
Nofollow backlinks are less common because they include a “rel=nofollow” tag that specifically instructs a search engine to ignore the URL. They’re typically used in instances where a link has been sponsored (meaning a company has offered some type of compensation to be included in a post), guest posts, and contract links. While they still direct traffic from one site to another, nofollow links provide little SEO benefit. The only caveat is that most search engines prefer well-rounded websites that include a balance of nofollow and dofollow links.
How to use backlinks
The act of adding a backlink in a content management system (CMS) is relatively simple; a user only needs the text or image to be linked and the URL itself. As mentioned above, the link alone automatically becomes a dofollow backlink, but a nofollow backlink requires the “rel=nofollow” tag to be added after the href attribute.
Some strategy is required for making backlinking work to improve SEO. While a publisher can theoretically add a limitless number of links to their content, those links are only beneficial for the site to which they direct traffic. Getting an external site to add a backlink is sometimes a tedious task that requires some degree of relationship building with fellow publishers. Sometimes backlinks happen organically, but they are frequently facilitated by publishers looking to improve their SEO ranking.
Google’s Search Console quality guidelines specifically outline link scheme violations, or backlinks used for the sole purpose of manipulating a site’s search ranking. Therefore, these types of links negatively impact SEO, so digital marketing experts should avoid buying or selling links, using links that are unnatural, or excessively exchanging links with another site. In 2012, Google released an algorithm update (codenamed “Penguin“) that penalized publishers believed to be in violation of its backlinking guidelines.