Backlinks are an important part of Search Engine Optimization (SEO). A backlink is an incoming link to a website. In the past, prior to the days of the search engine, backlinks were the main way to get from one website to another, however it has now become an integral part of Search Engine Optimization.
Search engines use the number of backlinks to a website as a part of their overall ranking algorithm (which can include a link-based ranking algorithm) that rates and ranks sites based on the search terms, the sites importance, and its popularity. Backlinks to websites from other sites are viewed by search engines as a positive vote for that site. In other words, if Site 1 had a link on their website to Site 2, it is a vote for Site 2, by Site 1. As a result of this, many sites use a technique that is known as linkspam which is an attempt for companies to place as many inbound links to their website as possible, regardless of the reputation and context of the originating site.
There are many factors that determine how much value a backlink adds to a website. Backlinks that are from trustworthy sites sites such as professional sites on a certain subject, or government (.gov, .mil) or educational sites (.edu) could contain more value than a backlink on a .net site or other non-professional top level domains. More recently, with an increase in the number of social media users, especially twitter, companies have been posting a lot of backlinks on twitter which can also increase their ranking.
Another essential factor is the anchor text (descriptive labelling) of a hyperlink that appears on a web page. When search engines index and crawl websites, the bots look at the anchor text of a hyperlink to determine the links relevancy to the content of the page. In many cases, websites contain certain links that they don’t want to associate their reputation, or cannot vouch for the content that appears on those pages, they can use the rel tag with the nofollow attribute within the hyperlink to prevent these links affecting their ranking. Other uses for the rel=nofollow tag is to prevent paid links and advertisements, and untrusted content such as blog comments from being associated with the reputation of your website. Additionally, you can also use the rel=nofollow tag for links that you do not want indexed with search engines.
The downfalls of creating too many backlinks, is that when created over a short period of time, it has the potential to reduce the search engine ranking of a website.
Hyperlink Syntax
