Google's pagerank is shown most commonly by the green bar in the Google toolbar in your browser (if you have it installed). While Wikipedia says this ...numeric weighting from 0-10 for each webpage on the Internet... denotes a site's importance in the eyes of Google,
this is no longer true. Pagerank is now a deceptive, essentially useless number leading many to make bad decisions (e.g., buying ads on sites based on pagerank, when foreseeable results will actually disappoint).
There was a time, a few years ago, that Google's pagerank was a great indicator of how much traffic Google would send to a site. After that traffic got to the site, the site would have a chance to connect with, or sell things to those visitors. That is no longer the case, pagerank is no longer very important and like so many things online and in life, numbers aren't everything.
In all things, the shorthand of a number seems convenient, but is likely useless for revealing the most important truths (e.g., "I love my parents 72" is fairly meaningless).