Just a related note in passing: On October 6, 2013 Matt Cutts (Google’s head of search spam) said Google PageRank Toolbar won’t see an update before 2014. He also published this helpful video that talks more in depth about how he (and Google) define PageRank, and how your site’s internal linking structure (IE: Your siloing structure) can directly affect PageRank transfer. Here’s a link to the video: http://youtu.be/M7glS_ehpGY.
PageRank was developed by Google founders Larry Page and Sergey Brin at Stanford. In fact the name. PageRank is a likely play on Larry Page's name. At the time that Page and Brin met, early search engines typically linked to pages that had the highest keyword density, which meant people could game the system by repeating the same phrase over and over to attract higher search page results. Sometimes web designers would even put hidden text on pages to repeat phrases.
Search engine optimization is a key part of online marketing because search is one of the primary ways that users navigate the web. In 2014, over 2.5 trillion searches were conducted worldwide across search engines such as Google, Bing, Yahoo, Baidu, and Yandex. For most websites, traffic that comes from search engines (known as "natural" or "organic" traffic) accounts for a large portion of their total traffic.
I dont know if Google gets its kicks out of keeping Search Engine Marketers and Webmasters jumping through hoops – or if they are in cahoots with the big SEM firms – so that they get this news and these updates before the average guy on the street. Either way, they are seriously getting a bit too big and powerful and the time is RIPE for a new search engine to step in and level the playing field.
The PageRank algorithm outputs a probability distribution used to represent the likelihood that a person randomly clicking on links will arrive at any particular page. PageRank can be calculated for collections of documents of any size. It is assumed in several research papers that the distribution is evenly divided among all documents in the collection at the beginning of the computational process. The PageRank computations require several passes, called "iterations", through the collection to adjust approximate PageRank values to more closely reflect the theoretical true value.