You should use a metasearch engine if you need more results than you would from a regular search engine. You can also use certain metasearch engines like Ixquick or StartPage if you are concerned with privacy. Metasearch engines are usually not search engines themselves. They redirect traffic to actual search engines and then return the results. That can help privacy since the largest search engines record the details of your search. If you use a metasearch engine, then all the large search engines would have is that the metasearch engine performed a search on their sites using whatever terms at whatever time. If the metasearch engine doesn't record your search details, then it would be harder to trace the search back to you.
Generally speaking, meta search engines perform searches using a conglomeration of other search engines. Metasearch engines enable users to enter search criteria once and access several search engines simultaneously. Metasearch engines operate on the premise that the Web is too large for any one search engine to index it all and that more comprehensive search results can be obtained by combining the results from several search engines. This also may save the user from having to use multiple search engines separately.
New popular metasearch engine http://www.tripleme.com which fetches from MSN, Yahoo, Google and displays results on one screen in multi columns side by side. Supports local and global search, all languages, all results, spelling suggestions, duplication links removing option. Also, you can compare performance of different search engines.
Search engine usually have their own database of sites they craw and list in their database, for example Google, Yahoo, Ask. Meta Search Engines usually do not have their own database of crawled sites, they search the databases of real search engines, usually many search engines at the same time, and provide you results. So a meta search engine will give you results from say Yahoo and Google, some meta search engines do have database of sites submitted to them. Example of a meta search engine is DogPile.
Google all the way matey
Google is both a website and a search engine. All internet search engines are websites, but not all websites are search engines.
I posted the list of search engines from wikipedia in the related links box below.
filiter not search the web
The internet is a means of connecting computer resources it is NOT the biggest search engine. Search engines are IT applications attached TO the internet.
The extraordinary growth of the internet has made it difficult, if not impossible, for search engines to keep up with its immense size and pace. Thus far, the major search engines have only been able to index a fraction of all the data that is available on the internet. Therefore, chances of finding relevant search results occasionally fails if users rely on only one search engine. Thus, the key to effective internet searching is not to rely on one, but rather on multiple search engines. However, it can be time consuming and tedious to individually visit and perform a search on multiple search engines. A Meta search engine (MSE) is a search engine that collects results from other search engines, and then presents a summary of that information as the results of a search. The MSE iral is a Web service that offers such functionality. In practice, one can adopt different approaches to achieve the same goal; one could build a unique Web service that fulfils all tasks and does everything. With a smaller granularity, iral Meta search engine is a service for each search engine and an extra one that will use all the other to retrieve the results and compile them.
There are too many different kinds of search engines to just give a number, so click on the link below for a full listing of all the different kinds of search engines.