PageRank - definition
The term PageRank, patented and trademarked, is an algorithm developed in 1998 shortly after Google was founded, and named after one of the company’s founders, Larry Page.
Based on link popularity, Page asserted that the web, or any other collection of entities could be ranked through reciprocal references.
Google PageRank was the basis for the original Google algorithm that measures the value of links to measure a website’s value. A link from page X to page Y is considered a vote by page X for page Y. The value of page X’s links to page Y is determined by how many votes of its own page X has from other sites linking into it. A page that is linked to by many other high-ranking pages gains a high rank itself.
While PageRank continues to provide the basis for much of Google’s search tools, many other factors are now included in the algorithm that have added value and mitigated vulnerability to sites with falsely inflated PageRank.
PageRank value surfaces on the Google toolbar in most browsers, but must be evaluated for what it represents – link popularity – as one aspect of a website’s effectiveness in the search engines.