nofollow Tell the search engine to not follow the link on this page and tell the search engine to follow the link on this page.
nofollow
For the Nofollow webmasters, the search engine states that "do not follow the links on this page" or "do not follow this specific link"
Nofollow link features do not allow search engine bots to follow links. Only humans will be able to follow the link. This means that if the website owner is linking you back with anophophilic features, then it does not pass through the juice of the link. Always use the nofollow link attribute on those links, where you do not want to pass the link-juice.
nofollow
<a href="http://www.google.com/" rel="nofollow">Google</a>dofollow
Dofollow links allow Google (all search engines) to follow and access our website. Linking the link and a backlink to us if a webmaster is linking you to this link, both the search engines and the humans will be able to follow you. The best way to give someone a doggie love is to allow keywords in anchor text. This means that when you are linking to any website or page, use the targeted keyword as an anchor text.
Example of dofollow
<a href="http://www.google.com/" rel="follow">Google</a>
OR
<a href="http://www.google.com/" rel="follow">Google</a>Note: By default all the hyperlinks are dofollow. So, you don't need to do anything to make a link do-follow.
Types Of No-Follow
follow links on the full page
Robots Meta Tag : <meta name="robots" content="nofollow"/>This tells bots/crawlers/spiders not to follow links on the full page.
Example
Link Attribute : <a href="http://www.google.com" rel="nofollow">This tells search engines not to count the link in terms of ranking pages.