Search engines appeared from the very beginning of the Internet. The idea was to enable users to quickly access the data they wanted to see. The primary idea behind the search engine is to ‘crawl’ the entire internet in search of a given string (or keyword) and provide the users with results that would be most relevant to the keyword. As the Internet grew, reaching over 1 billion sites in 2015, the task of the search engines became harder and required developing more and more sophisticated algorithms to provide users with best possible answer to their searches. Nowadays, most search engines can interpret long tail keywords even phrased in natural language.