The name PageRank is a trademark of Google, and the PageRank process has been patented. However, the patent is assigned to Stanford University and not to Google. Google has exclusive license rights on the patent from Stanford University. PageRank is a link analysis algorithm, named after Larry Page who developed it. PageRank is based on citation analysis and it measures the relative importance of documents linked to each other. It takes into account the number of links or references and the value of them. Google uses PageRank to rank Web pages. It is also used as a model for the evaluation of the quality of citations in scientific journals.
The calculation of the PageRank is available at http://en.wikipedia.org/wiki/PageRank.