What's the difference between follow and nofollow links?

[A289]

I understand this may be a really dumb question and from my understanding there is a piece of code in some url's that tell search engines not to follow that link. I am interested in finding out what the purpose of nofollow links are and how they apply to search rankings.

Thanks for the help

[IainReloadMedia]

Thanks for the insights.

It really helps

[A289]

Thanks Tait,

That is awesome information and thanks for responding so thoroughly!

[TaitLarson]

Spiders from search engiines "crawl" the web by following a link from one page to another.  Using a rel=nofollow HTML attribute on a link tells the search engine not to follw the link and crawl the page that the link points to.

Search engine rankings by sites like Google are based on the premise that the best content has the most links to it (this is a super over-simplification, I know).   "nofollow" links aren't counted by Google when they assign value to the page being linked to.

Most often sites use "nofollow" to block links from user generated content that might be used to manipulate search engines.  An example of this might be a blog that nofollows all the links in it's comments so that spammers don't show up and flood the comment section with links to sites they'd like to rank higher in google.

[Aftermath_SEO]

Basically, a link with rel="nofollow" will not pass link juice to that page.

The nofollow can be used to link to outside content without passing link juice, and is widely used in many sites with user generated content and profiles to prevent link spamming.