Search engine is a special tool that is used to search any information in the World Wide Web. Most search engines work in this way: the user types in a keyword, and searches against it. The results that match the entered keyword are displayed. This display of related web pages is technically termed as hits. Some search engines extract data from online web directories.

Web search engines stores information about websites using the World Wide Web. It has specialized programs known as crawlers that regularly visit web directories to fetch information. Next, the information is indexed properly using optimized algorithm. Better the algorithm, better will the presentation of the search results. Now, whenever a user searches with a keyword, it is matched with the indexed information and is presented to the user. In most cases, the websites are displayed in the order of the most distinct visits received by a site.