Many search engines have a "simple" search engine page for novice users and an "advanced" pages for more experienced searchers.

In some cases, being able to control how a search engine searches for a keyword or keywords may greatly improve your results. The "simple" search engine pages may or may not offer any of the more advanced controls for using advanced search techniques. Even the "advanced" pages may offer only limited ways for users to control the search engine. When using an engine unfamiliar to you it is often best to start by reading the "help" page to learn how you may be able to control the engine.

In addition to ways of controling how a search engine works you may also be able to restrict the search to specific areas and/or control how the results are displayed.

NOTE: Many search sites are actually powered by other search engines - AOL uses Google, Lycos uses Alltheweb, Hotbot will use either AllTheWeb.com, Google, Inktomi or Teoma (you choose).

Metasearch engines
Some search "engines" like Webcrawler and Metacrawler allow you to search using a number of different search engines combined. Because you can use several different search engines from these single sites, the ways you can control the searches are limited to very simple options - the ones that all of the engines have in common.

Specialty search engines
Some search engines are geared to finding specific information or only searching a specific site. The search engine on the medical information site WebMD only searches for webpages on its own site. The search engines Froogle (powered by Google) and MySimon and are shopping serarch engines. Google has a search engine (goups.google.com) that will allow you to search through Newsgroups.