Search engines do keyword searches against a database.
They are used to locate specific information. If you don't find the information you're seeking, try another one of the search engines, as they are built in different ways and often yield different results. Subject guides, such as Yahoo , LookSmart , and Magellan , organize sites into a hierarchy of categories. They are particularly useful for browsing general topics. Metasearch sites or metacrawlers such as Inference Find, Mamma , Metacrawler , and Cnet Search send your search to several search engines.