Search Engine Ranking

Search engine ranking is a measure of the online promotional success of a web page or website. Most search engines default to ten organic or natural listings per page. Many include sponsor links before or to the right of the results. Many searchers will be satisfied with the first page or two, so getting a top 20 or 30 listing can have an impact on a website's success.

Pagerank, Developed at Stanford University by Larry Page and Sergey Brin, is a link analysis algorithm which 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).

Google describes PageRank saying:

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 more than the sheer volume of votes, or links a page receives; 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".

References: Wikipedia
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