How do search engines work?
Search engines could be described as a library, but instead of books, they store copies of over a hundred billion websites and web pages in an index. When a user performs a search on a search engine such as Google, the search engine scans through its index to find the web pages that provide the best match for the specific search term. The search engine then ranks the web pages on relevance – a process based on more than 200 different criteria. The result of this ranking is presented to the user as a search result.