page ranking yahoo toolbar

How does the google page rank thing work?

It ranks my yahoo answers profile 7/10…i don’t think my profile is anything special that attracts people all the time. There are other top users here: http://answers.yahoo.com/rank_total;_ylt=AgaFt_BY75RD6HB6WLNNLBLsy6IX;_ylv=3 and the No1 user here (points wise) is ranked 5/10 so why is that? How does the “Page Rank” on the google toolbar actually work? i’m nothing compared to SK!?!
Oh and i’ve just noticed that even Yahoo! Answers is ranked 8/10!!

http://en.wikipedia.org/wiki/PageRank

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