Google�s visionaries, Larry Page and Sergey Brin, were the first to invent a measurement to determine and assign a specific value to a website's popularity and authority. The name for this mathematical model and resulting value is called PageRank and it forms the basis for how Google works. PageRank is in fact the technology that gave Google its competitor-killing edge, a way to greatly improve the relevancy, accuracy and validity of a search result to match a user's querey. PageRank is a trademark of Google. In essence PageRank provides a means to determine the value of a website for any given search term or keyword phrase. This value is determined by how websites link together with the more popular (and theoretically better) sites receiving more links. It�s these incoming links that help the site have a high PageRank value and thus display higher up in search results. Why is this important to measure and track? The higher your site's page rank, the more trusted your site is considered by Google and consequently you will have much greater chances placing high within organic search results due to a high page rank. We have listed many free seo tools to check your site's google page rank, AKA google PR.