How ranking works
The ranking of sites depends largely on the relevance of resources. The better the site answers the question, the higher its relevance and, accordingly, the higher the position in extradition.
When ranking is not only relevant resource to the subject (relevant sites are many), but also the convenience of the site for the user.
Search engine spiders first scan all the sites, and then index them. Evaluate the compliance of pages with key queries, technical characteristics and other factors.
Then, when the user enters a query, the search engine instantly gives pages from the database in descending order of relevance. This is the ranking.
For each user, search engines create personalized results – taking into account the history of searching on the Internet, geolocation. Therefore, the results differ from user to user.