Google PageRank, named after Larry Page, is an algorithm which is used by Google to assign a numerical weight to website pages. A websites PageRank reflects Google’s view of the importance of that web page. Website pages which are considered important are given a higher Google PageRank and are likely to show up at the top of Google search results. While PageRank is not the only factor used by Google to rank websites, it is an important one.
PageRank was developed to as quoted by Larry Page “understand exactly what you mean and give you back exactly what you want” which has innovated the way searches are conducted. Google’s search technology software is able to perform a series of simultaneous calculations in just a fraction of a second. Google uses over 200 factors including PageRank to determine web page importance, while many traditional search engines mainly rely on how often the web page contains a word. Google’s search results algorithm helps to provide searchers with the most relevant results on top.
Every website page is assigned a Google PageRank from 0-10. The higher the PageRank the more important the site is in Google’s eyes. The main factor used in determining a website’s PageRank is the quantity of inbound links and the PageRank of the web pages providing the incoming links.
A website page with many incoming links from pages with a high PageRank will also receive a high PageRank. If a website page has no incoming links then it has no supporting PageRank. Calculating a Google PageRank is a very complex mathematical process. The PageRank of a webpage that links to your webpage is important but the number of outbound links on that page is also an important factor. The more outbound links on a page the less the PageRank value your webpage will receive from the link. For example, a web page with a PR5 and only 10 outbound links is worth more than a link from a page with a PR8 with 100 outbound links. While incoming links help a PageRank link farms which house outgoing links to hundreds or thousands of sites should be avoided.
In addition to incoming links Google uses a variety of other factors to determine a PageRank. While Google itself will not provide details on these other factors influence on PageRank the known factors include: the number of visits to the page, the relevance of search words on the page, the format assigned to text, the placement of each word on the page and another large factor is the number of pages on a website.
This is just a shortened explanation of the Google PageRank algorithm, click here to read a more detailed explanation and see sample calculations.