Every time you type in a query in a meta-search engine, it searches a series of search engines and directories at the same time, compiles their results, and displays them either by search engine employed or by integrating them in a uniform manner, eliminating duplicates, and re-sorting them according to relevance. You are using multiple search engines all at the same time. By using a metasearch engine, you get a snapshot of the top results from a variety of search engines (including a variety of types of search engines), providing you with a good idea of what kind of information is available.
Meta-search engines are best to use when you want a general search, and don't know where to start - by providing you results from a series of sites, they help you to determine where to continue focusing your efforts. They also allow you to compare what kinds of results are available on different engine types or to verify that you haven't missed a great resource provided by another site, other than your favorite search engine. Overall, they're a great way to save time. Some good meta-search engines are:
Metacrawler -- http://www.metacrawler.com
Mamma -- http://www.mamma.com
Dogpile -- http://www.dogpile.com -- My favorite!
Research on the World Wide Web
Research for a paper or project should never be done solely on the World Wide Web. Good research combines various sources (books, journal articles, news stories, etc.) for a well-rounded outlook on your topic.
Search engines are remotely accessible programs that let you do keyword searches for information on the Internet. They are collections of websites (a database) that are created by machine. There are specific computer programs (called spiders or robots) that go out into the Internet, bring back websites, and store them. Google is an example of a search engine.
Directories or Indices are information resources that contain references to other resources, categorized by subject, usually in a hierarchy. Subject indices are not to be confused with search engines. Directories are created by people who actually visit the website or at least determine the subject matter of the website and place it in the proper category. Yahoo is the most popular Internet subject index.
Search engines give you a great amount of information but this information should be combined with a search in some directories as well. If you prefer to start with websites that are more organized into subject matter, use a directory. You should always search more than one place to get information and evaluate and compare your results.
When you find a search engine that you like or are comfortable with, go to the help area or the area that gives you tips on how to search. By looking over this information, you can easily become a very proficient searcher and will be able to do great searches quickly and easily.