About Do follow
Dofollow Link is a hyperlink that is able to tell all search engines to pass along it’s page rank influence to an outbound link.
If you will use or get do follow links then search engines will count your link in the eyes of google, yahoo, bing etc as backlink for your site and you can get some positive value for your site ranking.
Dofollow Link= < a href=”http://inproblog.com”>
About Nofollow Link
Nofollow Link is exactly the opposite. It is a hyperlink that removes the ability to pass on it’s page rank status to other sites.
Nofollow are for not crawling a link by search engine that influence the ranking of a particular website or blog in search engines.
Nofollow Link= <a rel=”nofollow” href=”http://xyz.com”>
How do “Dofollow” and “Nofollow” Links Work?
If you are optimizing your blog or website for search engines you have to get as many links pointing to your website as possible. Dofollow and Nofollow are two important factors among many SEO Ranking Factors.
How Search Engines Use
Never adhered to NoFollow. It’s not a search engine anymore.
They looks NoFollow links but simply does not pass on Google Page Rank to an outbound link that is tagged with the value.
Bing may not follow NoFollow link, but it does exclude it from ranking calculations.
Yahoo follows NoFollow links & excludes the link from all ranking calculations.