Slide 5 of 9
Notes:
Search Engines map the web - they use programs that visit sites, either submitted or linked to, and stores their contents in a database. We can then search the databases through a web page interface. E.g., Google, Alta Vista, Lycos, HotBot.
Meta-Search engines search multiple search engines at the same time. They take your search request and send it to a bunch of search engines and return all the results together. E.g., Dogpile, AllTheWeb, MetaCrawler.
Indexes (indices) are categorized lists of links to other sites. These don’t list as many sites as Search Engines, but return a high quality selection of links. The best known of these is Yahoo!, others include dmoz.org. LookSmart, and About.com.