| How Search Engines Work |
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First and foremost a search engine is an application written to crawl, or spider the web and find new content. Often companies misinterpret a directory as a search engine. The major differences between the two are the facts that one is automated and the other is man powered. The two leading search engines in use today are Google and Yahoo! , both are fantastic and both are relatively easy to “manipulate” if you know how they work.
Crawler based search engines such as Google or Yahoo! do just that. They have scripts that go out at regular intervals and “surf” the web. When they get to your website they’ll read your source code from top to bottom, left to right negating the markup to get the most accurate representation of your page. When the crawler finds itself upon a hyperlink it will follow it and do the same on the page its lead to. Once the crawler finishes its job of finding the information it passes it onto the second part of the search engine, the Index. The Index is a catalog of all the web pages the crawler finds, if the crawler hit a page that has been updated since its last crawl then that information is updated in the Index and the Index flags it as an active page. After indexing is completed information is sent to the search engine software. The software is the application that sifts through and filters indexed content based on whether or not it’s relevant to what the end user was searching for. How does a search engine determine your pages relevance? Crawling engines have algorithms in place that hit key points on your page to help them decide if you should be placed toward the top or bottom. First it will look at the title tag of the page. It deems this tag the most relevant and that should be where you start. Many companies only put the name of their company in the <title> tag and this is sufficient for human visitors but it tells very little to a search engine. We at citiREG put the name of each page in our title and other companies go as far as to put a very short description of the page in the title (i.e. citiBlog – Web Blog about Web Sites). The second place the search engine will look is in the meta information, or descriptive information. Every page should have keywords and a description assigned in its meta information, this tells the search engine what words you think are important to your page and also what your page is supposed to be about. Finally, frequency of keywords goes a fair distance in determining the relevance of your page. A crawler will notice if you have the keywords “health, food, exercise” in your meta information and those same words appear throughout your content or body. This tells the search engine that your keywords really are about your site and in turn the engine will give your page a higher ranking. There are does and don’ts to Search Engine Optimization (SEO) which I’ll explain in Fridays article! |