if you are not heard about PageRank then here is a short introduction.
Pagerank algorithm introduced by Google search that helps to rank a website in the search engine result page. PageRank was named after Google co-founder Larry Page which has a value of 0 to 10.
Suppose we have three websites named as A B and C and each website has a value of. 25. so if A, B and C point to 3rd website name as X then the website X value will be .75, because the summation of the three websites ABC is .75.
The simple formula of page rank is
PR(X)= PR(A) + PR(B) + PR(C)
Suppose that A has 3 links 1 Link point to X, 1 Link point to B and 1 Link point to C then total outbound links 3 and each link value now .25/3=.0833
Like the above B has 2 links, 1 Link point to X and another link point to C. Then total outbound link of page B is 2. And its links have value now .25/2= .125
Page C has no outbound links so its value is .25/1=.25
So now X value is X=.0833+.125+.25=.45
We can write Page Rank Formula as
If a page has a lot of incoming links then it collects PR from each pages pointing to it, in this way that page gets more importance in SERP. We can call this as a vote of a page. By this way, one page gets more importance then other if that page has more links. other words we can say that this link increases one-page reputation and status. one reputable page has good links can easily rank in Google SERP.
This make SEO a game of chasing PR. Link from high PR site it is the only way to rank high in Google.
By giving the tool of cheking Page Rank to the webmaster, Google gives the power to filter which pages link they accumulate to rank high on the search engine. Now, Google has stopped updating it toolbar so that outside google does not get the page rank of a Page. According to Google’s John Mueller “We are probably not going to be updating it [Page Rank] going forward, at least in the Toolbar PageRank”
From the above statement, we know that they use page rank for ranking factor but outside google nobody knows what is the page rank of their site.