Hello
Nofollow is an HTML attribute value used to instruct search engines bots that a hyperlink should not influence the link target’s ranking in the search engine’s index.
Types for No Follow:
1.Robots Meta Tag : <meta name=”robots” content=”nofollow” />
This tells bots/crawlers/spiders not to follow links on the full page.
2.Link Attribute : <a href=”
http://www.google.com” rel=”nofollow”>
This tells search engines not to count the link in terms of ranking pages.