PageRank is a family of algorithms for assigning numerical weightings to hyperlinked documents (or web pages) indexed by a search engine. Its properties are much discussed by search engine optimization (SEO) experts. The PageRank system is used by the popular search engine Google to help determine a page's relevance or importance.
Because Google has many different data-centers, your web page(s) can sometimes carry different PR values during updates. These are the PR values of your web page across Google's data centers.
