PageRank 如同個別網頁價值的指示器，透過龐大的連結架構來信賴網站獨特地民主性質。簡單來說，Google 說明網頁 A 連結至網頁 B 時，則視為網頁 A 投給網頁 B 一票。當然，Google 會查看票數來源，或是連結網頁接收的票數；同時它也會分析參予投票的網頁。透過「重要的」網頁來參予投票，並且幫助其它的網頁也成為「重要的」網頁資料。


重要、優質的網站會得到較高的 PageRank，同時 Google 會記住每次所處理的查詢情況。當然，如果查詢出來的網頁結果並不符合您的需求，重要的網頁對您也不具任何意義。因此，Google 將 PageRank 和精密的內文比對技術結合，來找出重要並且與您的查詢相關的網頁。Google 會將出現於網頁上的字詞顯示出來，並且檢查所有的網頁內容﹝及連結到此網頁的其他網頁內容﹞以決定這樣的查詢結果是否最符合您的需求。

出處:http://www.google.com.tw/intl/zh-TW/why_use.html




PageRank is a link analysis algorithm that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set. The algorithm may be applied to any collection of entities with reciprocal quotations and references. The numerical weight that it assigns to any given element E is also called the PageRank of E and denoted by PR(E).


PageRank was developed at Stanford University by Larry Page (hence the name Page-Rank[1]) and later Sergey Brin as part of a research project about a new kind of search engine. The project started in 1995 and led to a functional prototype, named Google, in 1998. Shortly after, Page and Brin founded Google Inc., the company behind the Google search engine. While just one of many factors which determine the ranking of Google search results, PageRank continues to provide the basis for all of Google's web search tools.[2]


The name PageRank is a trademark of Google. The PageRank process has been patented (U.S. Patent 6,285,999 ). The patent is not assigned to Google but to Stanford University.

site:http://en.wikipedia.org/wiki/PageRank

PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at considerably more than the sheer volume of votes, or links a page receives; for example, it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important." Using these and other factors, Google provides its views on pages' relative importance. Of course, important pages mean nothing to you if they don't match your query. So, Google combines PageRank with sophisticated text-matching techniques to find pages that are both important and relevant to your search. Google goes far beyond the number of times a term appears on a page and examines dozens of aspects of the page's content (and the content of the pages linking to it) to determine if it's a good match for your query.