Google PageRank or PR for short is numeric value assigned by Google to pages that represents how important a page is. The more important and known your pages are, the better PR they will get. PR is a scale from 0 to 10 where 0 is an unknown page for Google and 10 is the highest PR that can be assigned.

PageRank provides the basis for all of web search tools. It is always updated by Google in order to improve it and optimize it.

How is PageRank Calculated?
No one knows for sure how PageRank is currently calculated by Google (except Google itself ). Some speculations about the algorithm are made by webmasters all of them are based on the original PageRank published by Google.
In essence, Google interprets a link for page A to page B as a vote by page A for page B. This means that page A is considered important (at least by page B).
The more votes (more links) page A gets the higher its PR will be.

Going into more details
As stated above, the main factor in PR is links (or backlinks as they are called). But no all links weight the same when it comes to PR. So an 'important' page linking to you gives you more PR than a 'less important' one.
There for you should always try to get backlinks from pages that have a high PR. These will benefit your page the most.
Another factor in PR propagation is the number of out-links the 'voting' page have. So a PR4 page with only one out-link on it might give you more weight than a PR5 page with 100 out-links on it.
An typical example here would be the famous milliondollarhomepage. This page is PR7 page with hunderds of out-links therefore its weight is would contribute very little to your page PR.

How to increase my PageRank?
Well as you would have probably guessed, PR can be increased by getting more backlinks for your page. The more backlinks and the higher quality they are the more your PR will be.
Here are some tips:

• Submit your site to directories.
  
• Write important content to your site that would make people link to you.
  
• Write articles and distribute them.
  
• Although I don't recommend it but some people recommend it: Do link exchanges.
  
• Participate in forums (while adding your signature which includes a link to your site).
  
• Buy some links on high PR pages.
  

• Site age: The older the better, Google seems to like old sites.
  
• Backlink relevancy: Googles seems to be taking into account how relevant is the page linking to you, if it is not that relevant, the link won't weight much.
  
• Backlink duration: How long was the backlink up? The more the better.
  

Great tutorial mate!

There seems to be a update happening now.

That seems to be true! Some datacenters reflect some changes

There is also a backlinks update as well. and some datacenters have been updated big time.

Thank you for the great article! I always had questions about the Google PR and you have helped answered most of them. I am going to see what my PR is with the link you provided. Thanks again.

Good article for newbie>>
Here are examples>> http://www.webworkshop.net/pagerank.html

Many people are not realizing about fake page rank. You'll see people selling domain names with PR's but make sure you check to see if it is real.

Simple tool you can use is available here

http://www.seologs.com/pr-check/pagerank.html

nice article
very informative
starting to understand the pr

PageRank is a numeric value that represents how important a page is on the web. Google figures that when one page links to another page, it is effectively casting a vote for the other page. The more votes that are cast for a page, the more important the page must be. Also, the importance of the page that is casting the vote determines how important the vote itself is. Google calculates a page's importance from the votes cast for it. How important each vote is is taken into account when a page's PageRank is calculated.

PageRank is Google's way of deciding a page's importance. It matters because it is one of the factors that determines a page's ranking in the search results. It isn't the only factor that Google uses to rank pages, but it is an important one.

Thanks