Nofollow is a hyperlink on a web page with a rel= "nofollow" HTML tag applied to it. This tag directs search engines not to use or crawl the link for page ranking calculations. Since nofollow links are not counted by PageRank, they do not impact the search engine rankings of a web page.
In simple terms, these links do not get any attention or love from Google but can be beneficial to drive traffic to a website.
For example, ‘thank you’ pages, login pages, and blog archives are some pages that do not hold any value or helpful information when users land on them. Therefore, it is better to tell Google that you do not want these pages to rank in SERPs by adding a nofollow rel attribute to the URLs of these pages.
This is what a nofollow link looks like.
<a href=”http://www.aftership.com/” rel=”nofollow”>Link Text
According to Google Webmaster guidelines, the links with a nofollow rel attribute will not be used to determine a particular web page's ranking in search engines.
Are nofollow links important for SEO?
It would appear that if Google doesn't crawl or index a nofollow link for page ranking calculations, it doesn't hold any value in SEO.
Nofollow links, despite the fact that they do not hold any value to be considered for ranking, are still quite beneficial for SEO. These links might stop Google from indexing them, but users can still find them on search engines result pages or through a website.
For example, if you have a link to your site from an article on The Washington Post website, even if the link is nofollow, it's still a remarkably valuable backlink. It holds the potential to drive organic traffic to your website and is also good for your branding and building site authority.