In a hyperlink, rel=”nofollow” is an attribute added to the link to show that you are not passing any credit or endorsement to the page you are linking to
Nofollow was originally introduced by Google to limit comment spam and devalued all nofollow links, but they have since changed how the directive works.
Nofollow is now considered a ‘hint’ which means they may still use some information about linking patterns, but generally, still accept that no weight should be passed through the link.