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Hi Friends,
The following topic is about how Search Engine works.
SEO is a technique which helps search engines find and rank your site higher than the millions of other sites in response to a search query. SEO thus helps you get traffic from search engines.
The first basic truth is that search engines are not humans. While this might be obvious for everybody, the differences between how humans and search engines view web pages. Unlike humans, search engines are text-driven. Although technology advances rapidly, search engines are far from intelligent creatures that can feel the beauty of a cool design or enjoy the sounds and movement in *. Instead, search engines crawl the Web, looking at particular site items (mainly text) to get an idea what a site is about.
First, search engines crawl the Web to see what is there. This task is performed by a
piece of software, called a crawler or a spider (or Googlebot, as is the case with Google). Spiders follow links from one page to another and index everything they find on their way.
Having in mind the number of pages on the Web (over 20 billion), it is impossible for a spider to visit a site daily just to see if a new page has appeared or if an existing page has been modified, sometimes crawlers may not end up visiting your site for a month or two.
Crawlers are not humans and they do not see images, Flash *, JavaScript, frames, password-protected pages and directories, so if you have tons of these on your site, you'd better run the Spider Simulator.if these goodies are viewable by the spider. If they are not viewable, they will not be spidered, not indexed, not processed, etc. - in a word they will
be non-existent for search engines.
After a page is crawled, the next step is to index its content. The indexed page is stored in a giant database, from where it can later be retrieved. Essentially, the process of
indexing is identifying the words and expressions that best describe the page and assigning
the page to particular keywords.When a search request comes, the search engine processes
it – i.e. it compares the search string in the search request with the indexed pages in the database. Since it is likely that more than one page (practically it is millions of pages) contains the search string, the search engine starts calculating the relevancy of each of the pages in its index with the search string.
There are various algorithms to calculate relevancy. Each of these algorithms has different relative weights for common factors like keyword density, links, or metatags.The last step in search engines' activity is retrieving the results. Basically, it is nothing more than simply displaying them in the browser – i.e. the endless pages of search results that are sorted from the most relevant to the least relevant sites.
Hope this might be useful for all.
Thanks & Regards.
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