Pagerank is a page popularity indicator from Google. It is so well know because many people think that there is a strong relationship between Pagerank and the position of a site in search engines. There is a relationship, but it not that simple. When people who are just starting to learn about search engine optimization they are trying to simplify things to understand them. They will ask if the Pagerank influences the search engine ranking. It is mostly false. If you are new into this and want to simplify this, you should do it in the following way: “Google Pagerank and Google Search Engine rankings are a results of the number of links pointing to a page.
If a page have a high PR then you should assume that the page have wither a lot of backlinks, or few but quality ones. You should not assume that the page appear high in search engine rankings for keywords with high traffic unless it was well optimized for that keywords. Google pagerank does not take into account on-page factors and anchor of backlinks, 2 things which are very important for search engine rankings.
Pagerank is the fastest way to judge a website. If it has PR0 or PR1 then you shoulb know that the website have few and low quality links. If it is PR2 to PR4 then the website have decent links. If the PR is 5 or higher then people are linking to that site very often.
It is very easy to check the PR of a page, there are thousands of online tools for that. But the PR of a single page is not that important. If you have a blog with 500 articles, then you want to know which of your pages have more links than others, so you know which of them attracted links. For example, if you have a PR4 blog, you will have a lot of posts with PR0 or 1, others with PR2 and few with PR3 or 4. This means that those pages with low PR are linked only from other pages on your website. Pages with PR3 or 4 are pretty popular and receive a lot of links from outside.
So, how do you check the pagerank of all your internal pages ? You can’t just take every link and check it. You will lose a lot of time. WIP Check is the single application so far that will let you check the PR of all internal links. Unfortunately, it is not in a form of a wordpress plugin, but you can still download it and use on a Windows computer. Because it have to make thousand of queries to check the pagerank of every internal page, it will take a while until results are completed, but you may find out popular pages on your website that you were not aware of.