PageRankis a ranking system employed by Google that uses a numberto indicatehow important your website is on the internet. It works bymethod ofpages linked to one another. Every time a page links toanother, Googlesees that as a page giving away a point in favor ofthat page. ThePageRank value is based on how many votes or points thepage receivesfrom other pages. Likewise a page with a higher valuegives more pointstoward every page it links to, based on its ownpopularity beinghigher. Those pages linked to are then deemed popularby association,in essence. The amount of points or votes given awayby any given pageare unknown but are reflected in the page’s overallranking.
PageRankworks on a scale from 0-10, with 0 being the lowest and 10being thehighest.   Important to note as well is that PR(PageRank)works on a numerical system where each number isexponentially higherthan the last. So a PR of 3 is significantlyhigher than that of 2 inthe way that 2x2x2 (8) is much higher than 2×2(4), in fact it isdouble. As a general rule you should aim for a PR of3 or better foryour website.
Anotherfactor that influences PageRank is whether or not yourwebsite is richin valuable content. The importance of PageRank lies init being one ofthe ways Google uses to calculate where your websitewill rank in theSearch Engine results pages or SERPs.
If you would like to learn more about PageRank in-depth, read more on PageRank in this article by Ian Rogers.
Ifyou are unsure of how your website ranks, there is a cool free firefoxaddon that will allow you to easily determine the PageRank of your siteor any site you visit.
You can also check a website’s PageRank with this free tool.