Search engines search in the full text of web pages. They use indexes that have been created automatically by computer software. What search features that are available and how frequently the search engines are updated varies.
Yahoo Google Bing Exalead Gigablast
Web Directories
Web directories are organized by subject categories and are usually compiled by human editors. Common types of web directories are commercial, those with evaluated links and those edited by volunteer experts.
News search engines are search engines which continuously crawl and index selected news sources. Several of the larger search engines have their own news search engines.
Yahoo! News Google News RocketNews NewsNow Topix.net
Metasearch engines don't use their own index of web pages, instead they send search terms to several other search engines and/or databases and return the results from each one. Usualley duplicate hits are eliminated.
Surfwax Ixquick Metacrawler
Blogs is a popular publishing format on the Internet. Often blog search engines are combined with news search engines.
Technorati Newsisfree
Image searches
Image search engines specialise in finding pictures and animations etc. The largest search engines often have their own image search. There are also independent image search engines.
Google Images Yahoo Image Search PicSearch
Audio search engines
Audio search engines base their index either on complementary information on the audio file or in rarer cases on speech recognition and transcriptions.
FindSounds
Multimedia search engines
Multimedia search engine will locate audio, video, and music on the Web.
Yahoo Movies Blinkx
Search engines for email lists and discussion groups
This is not a list of image search engines but a list of search engines which present their results with visual representations and not only linear text.
Kartoo Quintura
It is important to be able to find the latest news and press releases from companies, governments, key agencies and organisations, research institutes.
Sometimes search engines are slow to index new web sites. Some sites can also be disadvantaged by link-analysis based ranking systems (e.g. Google).
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