What is Google PageRank?
PageRank is How well your page is ranked amongst other websites using google's link analysis algorithm. Noone except for the people at google knows exactly how the algorithm works.
What we do know: PageRank or PR is a value from 0 to 10.
0 being at the lowest end of link popularity, and 10 being in the top few websites in the world. This value is very important when calculating how much a website is worth.
Google PageRank Checker