The first fundamental truth you need to study about SEO is that search engines aren’t humans. While this might be clear for everybody, the differences between how humans and search engines analysis web pages aren't. Unlike humans, search engines are text-driven. Although technology advance quickly, search engines are far from intelligent or smart creatures that can feel the attractiveness of a cool design or enjoy the sounds and movement in movies. Instead, search engines crawl the Web, looking at exacting site items (mainly text) to get an idea what a site is about. This short details is not the most precise because as we will see next, search engines perform several actions in order to deliver search results – crawling, indexing, processing, calculate relevancy, and retrieving.
First, search engines crawl the Web to notice what is there. This task is perform by a piece of software, called a crawler or a spider. Spiders follow links from one page to a different and index the whole thing they find on their way. Having in mind the quantity of pages on the Web (over 20 billion), it is not possible for a spider to visit a site every day just to see if a new page has appear or if an existing page has been updated or modified. Sometimes crawlers will not visit your site for a month or two, so for the period of this time your SEO efforts will not be rewarded. But there is nothing you can do about it, so just keep silent.
What you can do is to confirm what a crawler sees from your site. As previously mentioned, crawlers aren’t humans and they do not see images, Flash movies, JavaScript, frames, password-protected pages and directories, so if you have tons of these on your site, you'd better run the Spider Simulator below to see if these goodies are viewable through the spider. If they are not viewable, they will not be indexed and processed, in other words 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 store in a database, from where it can later be retrieved. Basically, the procedure of indexing is identifying the words and expressions that finest explain the page and assigning the page to exacting keywords. For a human it not be possible to process such amounts of information but normally search engines deal just fine with this duty. Sometimes they might not get the sense of a page right but if you help them by optimizing it, it will be easier for them to classify your pages properly and for you – to get higher rankings.
When a search request comes, the search engine process it – i.e. it compare the search string in the search request with the indexed pages in the database. Since it is likely that more than one pages contains the search string, the search engine starts calculating the relevancy of each of the pages in its index to the search string.
There are multiple algorithms to compute relevancy. Each of these algorithms has dissimilar relative weights for general factors like links, keyword density, or metatags. That is why every search engines give different search results pages for the same search string. What is more, it is a known fact that all main search engines, like Google, Yahoo!, MSN, etc. periodically change their algorithms and if you want to keep at the top, you also require to adapt your pages to the newest changes. This is one cause to devote permanent efforts to SEO, if you'd like to be at the top.
The final step in search engines' action 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 appropriate to the least appropriate sites.
First, search engines crawl the Web to notice what is there. This task is perform by a piece of software, called a crawler or a spider. Spiders follow links from one page to a different and index the whole thing they find on their way. Having in mind the quantity of pages on the Web (over 20 billion), it is not possible for a spider to visit a site every day just to see if a new page has appear or if an existing page has been updated or modified. Sometimes crawlers will not visit your site for a month or two, so for the period of this time your SEO efforts will not be rewarded. But there is nothing you can do about it, so just keep silent.
What you can do is to confirm what a crawler sees from your site. As previously mentioned, crawlers aren’t humans and they do not see images, Flash movies, JavaScript, frames, password-protected pages and directories, so if you have tons of these on your site, you'd better run the Spider Simulator below to see if these goodies are viewable through the spider. If they are not viewable, they will not be indexed and processed, in other words 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 store in a database, from where it can later be retrieved. Basically, the procedure of indexing is identifying the words and expressions that finest explain the page and assigning the page to exacting keywords. For a human it not be possible to process such amounts of information but normally search engines deal just fine with this duty. Sometimes they might not get the sense of a page right but if you help them by optimizing it, it will be easier for them to classify your pages properly and for you – to get higher rankings.
When a search request comes, the search engine process it – i.e. it compare the search string in the search request with the indexed pages in the database. Since it is likely that more than one pages contains the search string, the search engine starts calculating the relevancy of each of the pages in its index to the search string.
There are multiple algorithms to compute relevancy. Each of these algorithms has dissimilar relative weights for general factors like links, keyword density, or metatags. That is why every search engines give different search results pages for the same search string. What is more, it is a known fact that all main search engines, like Google, Yahoo!, MSN, etc. periodically change their algorithms and if you want to keep at the top, you also require to adapt your pages to the newest changes. This is one cause to devote permanent efforts to SEO, if you'd like to be at the top.
The final step in search engines' action 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 appropriate to the least appropriate sites.
