PageRank is one of hundreds of ways Google determines the importance of a web page and where it should rank in relation to other web pages when people search for something related to the page. PageRank, named after Google’s Larry Page, was often incorrectly used by webmasters as a way to measure an “SEO score”. This was a bad practice, since PageRank is/was just one of many factors Google uses to rank a page. The Toolbar PageRank – the green bar added by many web browser plugins to see the PageRank of a given page, was updated very infrequently and was mostly a measurement of the number of incoming links to a page – not a measure of quality or popularity. This “Visible PageRank” was discontinued completely in March 2016. So SEO providers who were using “PR” to measure the progress of an SEO campaign were inaccurate at best, and were often intentionally misleading clients and misdirecting their attention to a false measurement.