Do follow and No follow

[rediscoverindia]

Do Follow
When Google bots are crawling a website they look for external links point to other websites. If this links is "do follow" then search engines will follows the link and so link juice gets passed. For eg:

<a href=http://www.xyz.com rel="dofollow"> xyz</a>
<a href=http://www.123.com rel="external"> 123</a>
Notice the rel="dofollow" and rel="external" in the above code. They define the link as do follow. Also if you do not use rel attribute the link will be treated as 'dofollow'. These links are important in terms of SEO as they are tracked by search engines and the value (which is called link juice) of the links also gets transferred.
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No Follow
If a search engine finds a "no follow" backlink it will just ignore the link and will not get deeper into crawling and no link juice is passed. Fo eg:

<a href=http://www.xyz.com rel="nofollow"> xyz</a>
Notice the "nofollow" attribute in the above code. This defines a code as "nofollow". So "nofollow" backlinks are not important in terms of search engines as it is not crawled. The comments section mostly have no follow links. But that does not mean that these links are useless. You can still get some quality traffic from these also.

For eg: you went to a well known website and you commented something which attracts readers attention then the reader might want to know more about you (as this is human tendency) which may help you in bringing some quality readers. So do not ignore it like search engines.