What is PageRank (PR)?
The PageRank gives information about the number of hyperlinks that point to a website. A new site is at the beginning refer a PR of 0 The more links to a site, the higher the PageRank. The higher the PageRank of the linking site, the greater the value. The PageRank is basically always calculated for each page and can be in between the value of 0-10.
Sample Calculations for PR2
100 Links PR1 > PR2 < 3 Links
Conclusion: In order to achieve a PageRank of 2 it requires either around 100 backlinks from PR1 pages or 3 backlinks from PR3 pages.
Sample Calculations for PR4
3000 Links PR1 > 550 Links PR2 > 100 Links PR3 > PR4 < 18 Links PR 4
Conclusion: The higher the quality of backlink the more value it is
PageRank & Google
Google evaluates every 4 weeks, the backlinks from. The PageRank is determined about 4 times a year. This means that depending on topicality a particular domain already has a different value.
How important is the PageRank for SEO?
The PageRank plays in the direct calculation of the SERPs (Placement on Google) which hardly matters. Rather it is the qualified backlinks a site has which are responsible for a higher position (and of course this also increase the PR).