"PageRank" an algorithm for assigning weightage to each page of World Wide Web is a patented trademark of Google. This has been patented to Stanford University rather than Google itself because the Google founder Larry Page developed this in Stanford University.

This algorithm may be functional to any collection of entities with mutual quotations and references. Page Rank depends on the individually self-governing personality of the web by using its big link structure as a meter of an one page's importance. In essence, Google depicts a link from page X to page Y as a vote, by page X, for page Y. But, Google looks at more than the complete number of votes, or links a page has; it also checks the page that casts the vote. Votes caste by pages that are themselves "significant" weigh more greatly and help to make other pages "significant".

Google gives a numeric weightage from 0-10 to each webpage on the Web; this PageRank denotes a site's significance with Google. The scale for PageRank is logarithmic like the Richter scale and approximately based upon number of incoming links as well as significance of the page giving out that link.

In different words, a PageRank is the outcome of a "vote count" among all other pages on the Internet about how significant a page is. A link to a page is counted as a vote. The PageRank of a page gets change regularly and relies on the amount and PageRank metric of all pages that link to it ("inbound links"). A page which is linked to by a lot of pages with high PageRank gets a high rank for itself.

Fake PageRank - Although the PageRank revealed in the Toolbar (Google Toolbar) is taken to be as resulting from a truthful PageRank for a majority of sites, it must be pointed out that this value is also simply changeable. An existing error is that any low PR page that is redirected, via 302 server header or "Refresh" Meta tag, to a high PageRank page makes the lesser PR page to acquire the PR of the target page. In theory a new, PR0 page with no inbound links can even be redirected to a site like Google.com - which is PR 10 - and in the next PageRank update the PR of the new page will be moved to PR10. This method, is also called "302 Google Jacking", is a recognized fault or bug in the structure. Any page's PR can be spoofed to a higher or lower figure of the webmaster's option and only Google can access the real PageRank of the page. Spoofing is usually checked by making a search in Google for a URL with doubtful PageRank, as the results will show the URL of a completely dissimilar site in results.