PageRank is one of the more than 200 factors that Google uses to evaluate and rank web pages on its SERPs (search engine results pages). It was developed by Lawrence “Larry” Page and Sergey Mikhaylovich Brin while working on their search engine research project “Backrub” at Stanford University, where they were both computer science PhD candidates. The term PageRank is derived from Larry Page’s last name; the “page” in it is not from “web page”.
Also known as PR, PageRank is essentially anumerical indicator of the importance of a web page. It is based on the concept of Sergey Brin that web pages could be arranged in a hierarchical order by “link popularity”, that is, a web page would get higher PR as more and more link to it.A PR0 web page is unimportant, while a PR10 (the highest PR possible) web page is extremely important.
And why should a web page with more links to it get higher PR than one with less links? The rationale behind it is, when someone really likes something and/or finds it really useful and/or has very good experience with it, he would naturally recommend it to others.So, if one links to a web page, it is like a recommendation or a vote for that page.
The more links (recommendations) that a web page gets, the more important it becomes, especially if the links are coming from unique sites.In addition, links from sites with high PR pages count more than links from sites with low PR pages. Like Sergey Brin, dubbed the Enlightenment Man by The Economist, said, “We came up with the notion that not all web pages are created equal. People are — but not web pages.”
So how exactly did Page and Brin come up with PageRank?As a candidate for a PhD in computer science, Larry Page needed a dissertation theme. He thought of the World Wide Web and its mathematical properties in connection to links. He decided to concentrate on discovering the link relationships between pages.
Sergey Brin joined Page in the project which they nicknamed “Backrub”. They developed a web crawler for the project to gather backlink data. Then they developed a probability distribution algorithm to analyze the data gathered by the web crawler in order to measure the importance of a particular web page based on the number and nature of the links to it. They named the algorithm PageRank and subsequently realized that it could become the basis of a search engine that would be better by far than the search engines which then existed.
So they built a search engine prototype, the first ever version of the Google search engine, and made it available through the Stanford University website in August 1996. The first paper about project Backrubwas published in 1998. It described PageRank and the initial prototype of the Google search engine. It was co-authored by Rajeev Motwani, professor of Computer Science at Stanford University whose research focused on theoretical computer science, and Terry Winograd, professor of computer science at Stanford University and co-director of the Stanford Human-Computer Interaction Group.
PageRank still forms the basis for all Google web search tools, and links from high PageRank sites will contribute more to boosting thePageRank of your own sites than links from sites with low PR. However, it is well to remember that it is not just PR that determines the rankings of your web pages on the SERPs. As mentioned above, PR is only one of the approximately 200 factors considered by Google when assigning rankings to web pages, and while it is very important, it is not the be-all and end-all of SEO.
So, if PageRank is not the be-all and end-all of SEO, why should we even bother with it at all? Well, the search engines do not exactly say what factors they consider when ranking web pages, and among the 200 factors that are used by Google, PageRank is one that is known. So we should make the most of it to give our web pages a fighting chance to get to the first page of, and ultimately to the number one spot on, the Google SERPs.