how to google search engine work
How do Google searches work?
I search a keyword "email list of uk hotels" in "http://google.co.uk ". The 14th result page is showing a google link. Why are they showing this result?
PageRank is an algorithm used by Google Search to rank websites in their search engine results. PageRank was named after Larry Page,[1] one of the founders of Google. PageRank is a way of measuring the importance of website pages. According to Google:
PageRank works by counting the number and quality of links to a page to determine a rough estimate of how important the website is. The underlying assumption is that more important websites are likely to receive more links from other websites.
Source: http://web.archive.org/web/20111... Archived from original page.
Google's Page Rank Algorithm is pretty cool. It uses the concept of random walks in a Directed Acyclic Graphs. I'll be very crisp and out of math in the answer. You can view the wiki for the math.
Consider all the webpages in the world as nodes of a graph. All the hyperlinks i.e mentions of a website on another website as the edges. For ex : I'll add a hyperlink to google on my personal webpage then it'll result in an edge from my webpage to google. So,in this way the graph is made.
Now,page rank basically ranks the webpages . So,a generic score needs to be assigned to every webpage upon which they'll be ranked. This score is dependant on the webpages that point it with a factor of alpha and a constant term with a factor of beta. The computations are made and the scores are computed till no further change in scores can be obtained.
From the above image the percentage indicates the scores/pagerank of the nodes. We can observe that even though C has lesser links it has a pretty high score because it is being pointed by a popular node .So,B shares some of it's score with C giving rise to such high values.
I've used a word called Random walk. If I am surfing a page and there are two hyperlinks from that page and I have to randomly chose one of them then there is 50 % probability of choosing a page. It is said that if you randomly keep surfing the webpages by clicking hyperlinks from a page then you'll eventually end up on a page with a high pagerank. With a probability of alpha perform random walk to one of it's neighbours and with probablity beta restart the surfing from some other page. Google uses beta =1 and alpha = 0.85 for calculations.
Now,you know what to do to increase the page rank of your webpage -
Consider all the webpages in the world as nodes of a graph. All the hyperlinks i.e mentions of a website on another website as the edges. For ex : I'll add a hyperlink to google on my personal webpage then it'll result in an edge from my webpage to google. So,in this way the graph is made.
Now,page rank basically ranks the webpages . So,a generic score needs to be assigned to every webpage upon which they'll be ranked. This score is dependant on the webpages that point it with a factor of alpha and a constant term with a factor of beta. The computations are made and the scores are computed till no further change in scores can be obtained.
From the above image the percentage indicates the scores/pagerank of the nodes. We can observe that even though C has lesser links it has a pretty high score because it is being pointed by a popular node .So,B shares some of it's score with C giving rise to such high values.
I've used a word called Random walk. If I am surfing a page and there are two hyperlinks from that page and I have to randomly chose one of them then there is 50 % probability of choosing a page. It is said that if you randomly keep surfing the webpages by clicking hyperlinks from a page then you'll eventually end up on a page with a high pagerank. With a probability of alpha perform random walk to one of it's neighbours and with probablity beta restart the surfing from some other page. Google uses beta =1 and alpha = 0.85 for calculations.
Now,you know what to do to increase the page rank of your webpage -
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