PageRank Means

What is PageRank?

PageRank is a unique algorithm developed by Google founders Larry Page and Sergey Brin at Stanford University and determines the importance of a web page measuring page importance on a scale from 0 - 10, where 10 is the highest. The main factor behind the PageRank algorithm is link popularity. If one site links to another site, then Google interprets this link as a vote, the more votes cast, obviously the more important the page must be. ...

From here on in, we'll occasionally refer to PageRank as “PR”.

Note:
Not all links are counted by Google. For instance, they filter out links from known link farms. Some links can cause a site to be penalized by Google. They rightly figure that webmasters cannot control which sites link to their sites, but they can control which sites they link out to. For this reason, links into a site cannot harm the site, but links from a site can be harmful if they link to penalized sites. So be careful which sites you link to. If a site has PR0, it is usually a penalty, and it would be unwise to link to it.