When someone is looking for an answer on the internet to a question, they use search engines. In order to provide users with the precise results they seek, search engine algorithms are computer programs that scour the web for hints. For any given keyword, search engines use algorithms to identify websites and choose which ones to rank.

Search engines operate in three stages: crawling, which is the finding stage; indexing, which is the storing stage; and ranking, which is the retrieval stage.