edit DoFollow links
A DoFollow link is a link on a web page that passes PageRank or link juice to the target web page being linked to. A DoFollow link is just a link that doesn't have the NoFollow attribute attached to it.
Here's an example of HTML code for a normal, or DoFollow, link:
<a href="http://www.Blogfullverion.com">Full verion software</a>
Compare that to the HTML code for a NoFollow link:
<a href="http://Blogfullverion.com" rel="nofollow">Full verion software</a>
On the Web, a DoFollow link to a website is like a vote for that website. Inbound links, or links from a different website, are something that search engines really pay attention to when deciding where to rank a web page in search results. Inbound links from a number of authoritative websites tells search engines that the target web page is important.
It's best to leave links DoFollow unless you don't trust the site you're linking to, or for some reason don't want people to find it in search results. A log-in page, for example, isn't really a page people search for.
If you're hosting a paid link, such as an ad, you should make it NoFollow. It can also be a good idea to make links in user-generated content, such as comments on blog posts, NoFollow.
For more detailed guidance on deciding which links to mark NoFollow, read No Follow Links Don't Help PageRank or SEO.
Here on AboutUs.org - the world's largest editable website directory - we link to every listed website. These links are NoFollow by default because we know that every site on the Web isn't great, nor necessarily worthy of our endorsement. We choose to follow the links on a website profile once we have reviewed the site and the page about it. See the AboutUs DoFollow links policy for more details.