Google PageRank was a calculative software which determined the relevancy of one web page based on the number of quality backlinks it contains.

In other words, PageRank views backlinks as votes, which means if Page X links to Page Y, Page Y is voted by Page X. The job of PageRank is to interpret both the page content and find relevancy. The higher is the relevancy level, greater importance is ascribed to a certain page by Google which positively affects the organic result of that web page.

Currently Google doesn’t use PageRank to rank a webpage. Google’s John Mueller said Google probably won’t update Toolbar PageRank in the future.