HotBot - Voted the best search tool by PC World . Google - Retrieves relevant results. Placement of results is based on an algorithm that determines how many other sites link to each site. Metacrawler - Sends a query to more than one search engine at a time. Meta-engines are great for saving time but since they don't adhere to all of the rules and idiosyncracies of each individual engine, they should not be equated with having performed a comprehensive search.
Search engines explore the web looking for a specific word or phrase.
Each engine has its own quirks and strengths. Yahoo - The best known Web directory. Has thousands of sites arranged in many categories. WWW Virtual Library - A Web directory with a strong academic focus and is arranged in long, alphabetical listings. Unlike Yahoo or Magellan, this site does not carry advertisements.