Dofollow
It is a type of link which has a potential to improve the ranking and the credibility of your website in Google. By default every link is dofollow, link which does not contain Rel=”Nofollow” Attribute is dofollow and these are considered to be the most powerful links for any websites.
These links allow search engine to doindex and pass link juice which is indeed the most vital thing for webmasters.The credit goes to Google who introduces dofollow link in 2005 to deeply filter search engine results for spam indexing.
If you want to know more about in detail that how to identify and make difference between both of these links then you must read out the valuable source along with video tutorial Difference Between The Code Of Dofollow And Nofollow Linkand you can also learn how to turn Nofollow in to dofollow and Dofollow in to Nofollow.